Friday, November 25, 2022

The QRP(p) powermeter revisited and more meter repairs

 


  8 years ago I did need a QRPp powermeter to measure an output of approx 10mW to use on WSPR. The original article on my blog showed a foggy photo and it was a job in a rush. In my current SWR/power meter repair I needed some resistors that were luckely still in this meter. So I decided to use them for the broken Stabo SWR/Power meter and rebuild the QRP(p) meter a bit. I also made better photos. I disabled the SWR meter function and only use the power meter part. To calibrate I use my FT-817 at 1W and adjust with the potmeter to full scale. Then I adjust audio to 100mW output and adjust the potmeter to fullscale again. After that I adjust audio till 10mW can be read on the meter. I realize this is an indication but I don't want to use attenuators because it would limit my receive as well.  At the moment I'm researching the possebility to experiment on 40MHz WSPR/FT8 with 10mW ERP without a license after some blogposts from G3XBM about this matter. 


  Back to the repairs. I bought a nice Stabo SWR/Power meter on the last radiorally I visited. Unfortunately this device was defective, I could read forward power but the pointer didn't move when I wanted to see my actual SWR or reflected power. At first I measured all diodes, all did show correct readings. Next I measured the switch, it was ok. Next the potmeters, I noticed on didn't have any resistance at all. After removing the thing I noticed why, it was broken. Now searching for 200 Ohm potmeters in my pile of electronic waste I could not find any good ones, most are in the K ohm range. So that is the point I decided to get them from my QRPp meter.



  This is the SWR bridge from the QRPp meter. It contains two 130 Ohm resistors. However the Stabo meter use 2 potmeters of 200 Ohm. I removed the resistors and soldered them in the Stabo meter. Readings are not correct. With a 50 Ohm load I read a SWR of 1,8:1. I reverse the input/output leads (TX signal at antenna side) to see of it would change but same reading there as well. 






  I think that is is a matter of a poorly designed pick-up transformer, actually no transformer as well. The signal pick-up is just 2 wires wrapped around the tube that is connected to the inner side of the connectors. You see this often in cheap SWR meters. Wish I could exchange the bridge for the one from the QRPp meter because that one looks a lot better and I know it is very accurate. Anyway in the end I replaced the resistor at the side of the reflected power pick up with the 200 Ohm potmeter that was still ok. 





  This time I could calibrate SWR almost 1:1 with a 50 Ohm load and 1:3 with a 150 Ohm load. Besides that I had to calibrate the power meter as well. It showed 3,5W when 5W was applied. Still it is not very accurate, even not after the calibration. I know the output of my FT-817 is pretty right what is should do. If I measure it with the Welz powermeter it shows right 0,5 - 1 -2,5 and 5W. With the Stabo it shows 0,6 - 1,2 - 2 and 4,8W.





  But at least it is repaired and I could use or sell it now.

Here the picture from both meters. Well, analogue meters might be a bit outdated. But it was fun to be able to repair something.

Then I remembered I had another broken meter. Well, it is a case of a meter that I never use. It's a Daiwa VHF/UHF SWR meter. Whatever power I put in both meters didn't move. I did a quick check on the pointers of both meters, they moved allright. So, easy as that something blocked the signal. Then I remembered I did a quick check before about 4 years ago and that revealed both switches are just very bad. Probabely corrosion because I actually never use this meter. I decided to use contact cleaner and compressed air to blow any corrosion off as far as it is possible from the out side.


Well, it worked well after some fiddling with the switches/air and contactcleaner. I measured all contacts and it was working again. Connecting the FT-817 showed movement of both meters again. Hopefully it will stay in good condition now. Or may be I should leave a note inside in case I have to open this meter again in about 10 years ;-)




Monday, November 21, 2022

SWR/PWR meter repair - hold your breath!

 So unfortunate I coincidentally dropped met precious Welz SP-15M SWR/Power meter. From the outside there was no real damage. But unfortunate the meter's pointer wouldn't move when applying power to it. I bought this meter in 2011 on a radio rally and it went with me at several portable occassions. It is a nice and accurate meter excellent for QRP and I don't want to lose it. So searching for a solution I arrived at the TRX lab youtube channel about the repair of a Diamond SX 600. At 4.05 minutes Peter shows a easy way to measure the mechanical voltmeter itself. So, I tried. Between the terminals my meter showed resistance. The meter is not stuck ( you find it on the internet as most common fault). But applying voltage on it with both the multimeter and a 1,5V battery the voltmeter still didn't show any movement. I also measured if the voltage pickup was correct when I was TXing and that showed that there was nothing wrong on that side. Not shure what to do now....I asked Peter and got the answer it could be a mechanical issue. Of course, there are not much electronics in a simple SWR/PWR meter. It consists of some coils, diodes, switches and a voltmeter. What else could it be?

After a good night sleep I was thinking that the fault could only be at the volt meter itself. For that I had to take it out of the housing. First of all I desoldered the wires and the capacitor that was soldered over both terminals, not the easiest job since wires were wrapped around the terminals. After some effort I got the bare meter in my hands and I could finally measure the meter again and.....it showed no resistance this time! To research the fault I had to take it apart. A very delicate job with my thick fingers. But as you can see on the photo I managed it.






Next thing was examine the actual inside for any damage with a magnifier since this is really something small. Luckely my phone has a excellent magnifier as well and I managed to picture the problem.


 Can you spot the problem? It is the small spring which is not connected to the terminal anymore. Remember this is very tiny. Personally I can only see it with a magnifier. To solder it you need a steady hand and hold your breath. At first I soldered it but the spring had moved in a wrong position. At a second attempt I got it right. A quick measurement with the multimeter showed resistance again and I saw the meter move as well. Now it was just a case of rebuild the thing and test it.

A quick test with my CB radio which previously showed that it has 3,5W out . After the repair nothing changed so I guess I don't have to calibrate the meter. Now I really need to be more carefull with my equipment. However it is a miracle this didn't happen before since portable use isn't always the best for this kind of meters. I might search for a digital alternative to bring with me in the field and keep this meter in my shack.

Sunday, November 20, 2022

Friese 11 steden contest 2022

 Since this is a primarily local contest I'll write this post in the Dutch language. If interested you're welcome to translate it with google in the language you prefer.

Vorige week was ik de PA-beker contest vergeten. De Friese 11 steden contest wou ik zeker niet missen. Dus toch maar in de agenda gezet en alles voorbereid. Voor degenen die het nog niet weten, de Friese 11 steden contest heeft natuurlijk te maken met de legendarische schaatstocht. Het doel in deze contest is zoveel mogelijk stations te werken waarbij rapport, QSL regio en plaatsnaam als uitwisseling geldt. De multipliers zijn de 11 steden van de beroemde schaatstocht en als 12e multiplier de kluunplaats Bartlehiem. 

Dit jaar werkte ik met de Icom IC-7300, 100W, Heil Proset Elite Ic headset en de antenne de inverted-V doublet.  Dit werkt al jaren prima en het was nu zeker niet anders. Wat mij opviel dit keer was dat er veel amateurs klaagden over veel storing en dan wel zo erg dat het hun ontvangst haast onmogelijk maakte. Zo hoorde ik PA1AT uit Yde die al na een paar QSO moest stoppen omdat hij gewoon niks meer ontving. Daarnaast was het aantal deelnemers gering, waarschijnlijk te wijten aan sport op TV? Het is maar wat je belangrijker vind. Zelf heb ik vrij snel 11 multipliers kunnen werken, alleen Hindelopen ontbrak. Waarschijnlijk was er geen amateur in of bij Hindelopen die aktief kon zijn op 80m, erg jammer, maar volgend jaar beter. Leuk om weer veel bekenden te werken, veel amateurs doen elk jaar mee. Het meest vreemde voorval deze contest was een PD amateur die mij zo nodig tot 2x toe een rapport moest geven. Voor alle duidelijkheid de amateur in kwestie is in overtreding en ik mag volgens de regels niet eens een QSO met hem maken wat ik ook niet gedaan heb. Ik ben niet van agentschap telecom en ook niet van de politie dus ik geef er verder geen commentaar op. Alles bij elkaar was het toch een leuke gezellige contest en kijk ik weer uit naar de volgende keer.


Friday, November 18, 2022

#60m TL8ZZ Central African Republic worked

 


Tnx to PA4O Peter I noticed that this DXpedition was now on 5356 FT8 F/H. After trying almost the whole week now it was easy to work them tonight.

Monday, November 14, 2022

#60m Guinea Bissau worked

 

Lucky this time. J5JUA was very strong and I found a empty spot in the waterfall...new one on 60m for me.

Sunday, November 13, 2022

DX sunday - Saved by PB7Z

 This morning I already noticed the bands would be full of DX. I hoped for some nice DX contacts. But with the WAE RTTY contest on it was a bit difficult to receive the DX. Talking about contests, I totally forgot the PA-beker contest today.


I only had time in the afternoon/evening today. And while I write this I still hope for some DX showing up on 60m. I saw TL8ZZ Central African Republic) and FJ/SP9FIH (St. Barts) yesterday evening but was too tired to continue calling in the huge pile-ups.

Today my QSOs almost didn't happen, I had the luck I had some back talk with PB7Z via internet. We were both trying for TL8ZZ on 12m. But after one hour trying I decided to QSY 10m to try. Just when I switched to 10m I got a message from Bernard that TL8ZZ was replying to me. So I immidiatly switched back to 12m and made the contact after all. Wow, if Bernard had not seen it I would have missed them. After that I went to 10m and worked them after calling once. At the same time FJ/SP9FIH was on at 10m only 1 KHz above TL8ZZ. I turned the beam and made the contact. The benefit of having a directional antenna! Talking about that, a bit later Bernard warned me T88WA appeared on 20m. I could barely see him between the RTTY sigs. But I managed to get him to reply to me. Only the RR73 was just on the stream that I could not see. Luckely Bernard has a beam and came to the rescue, He received the RR73 and send me a copy to verify. Well, it was a bit strange....something like a hybrid contact. Some will say this is not valid, however I'm in the log...


On 30m I worked V51LZ (Namibia) and HB0/HB9LCW (Liechtenstein) both new band ones. 

Hey I do some SSB as well if time allows. The problem is that I have to be in the shack actually. FT8 is done mostly remote from my laptop/tablet or phone. On SSB I worked Phil K4OMD from Ft. Lauderdale FL. He is a belgium guy and we talked in our native language Dutch. I also worked V31XX (Belize) on 10m SSB after I worked him on 12m SSB yesterday.

Thanks to PB7Z this was a successful DX day.


Friday, November 11, 2022

FT8 basics that some HAMs still don't understand

 Not that I am an expert in FT8 communications but some basics are still not understood in the HAMradio FT8 community. I thought to just write them down here and hope someone will learn from it.

On the TX side:

 First of all I want you to understand that almost every transceiver has a transmit audiofilter. Dependent on your transceiver this audiofilter can be set at wide or small. But even on wide, it will not be wide enough for digimode covering a bandwidth of about 3000 Hz with maximum audio. To transmit with a constant maximum audio frequency you need to use "fake split" to set the transmit frequency to compensate in that way you always transmit at maximum of the audio transmit filter. Of course this only works if your radio is connected via CAT control to the software. The benefit is that you will not transmit distorted audio and harmonics (cleaner signal) and you will have equal power output all over the FT8 frequency spectrum. Of course I assume you understand how to setup the audio output to the transmitter, it should transmit with minimum ALC.

A beautiful signal from HA8BE on the 60m band. Wipes out most of the signals...

I've been posting about this before: https://pe4bas.blogspot.com/2021/01/to-all-ft8-lovers.html

On the RX side:

 Second is the RX bandwidth. Of course, if you use an old radio, you will be limited to about 2500-2600Hz. But most HAMs these days are getting more sophisticated equipment, especially those that are interested in the digital communication modes like FT8. A very populair radio, for instance, is the Icom IC-7300 which is a SDR radio. It can listen to a bandwidth of 3600Hz. I know other more sophisticated SDR radios can listen to 4000Hz or even more. Still most of the FT8 QSOs going on are limited to 200-2600Hz. Why?  Really, is this my misjudgement? Are most FT8 users equipped with 20 year old transceivers? I don't really think so. Spread out! Use the whole bandwidth... 

20m on a random time. A lot of spectrum is free to use!

Deliberate QRM?

It is also wise to check the DXcluster and Hamspots.net before you transmit. So many times I see stations transmitting at exact the same spot in the waterfall as a DX station they probabely do not hear. A empty spot in the waterfall does not always mean it is actually free to transmit. It can happen by accident of course. Most times you will be notified by others to QSY (change frequency).






Just an example

 Have you ever been listening to DXpeditions that transmit with F/H (Fox/Hound). This is a great invention. What I do not understand is sometimes stations are calling in the same period as the DX. I really don't understand? Why calling if you don't see the DX station at all? Do they think the DX stations wil mysteriously get out of the noise for them.....or magically change periods just for them? Strange things happen....come on....check if you are in the right period! Sometimes this happens by accident...though I have seen stations calling in the same period of the DX for over 30 minutes.

Well, have you seen anything annoying on FT8 (or other modes)? Have any tips for others? Please comment. Hopefully someone has learned from this post.

Wednesday, November 9, 2022

TBDXC Bands Alive HF Ultra Marathon - good to know!


  Remember my posts about the True Blue DX club HF marathon? Probabely not. It's one of many marathons over the year. This one is particulary for CW and SSB. The club wants to increase the use of SSB and CW on the (HF) HAM bands. A nice thought and I welcomed it. I registered for their marathon since you don't have to be a member to participate. I uploaded my logs and became 6th in 2021. A nice certificate was received. I thought it would be nice to upload my log to this years marathon as well. I did....but then I got an e-mail. Too long for this blogpost to just copy&paste it here so I publish the most important part:

Therefore, if you enjoy FT8, or you use it ‘because there is nothing else’, or to work a new one ‘no matter how - just as long as I put it in the log’, we wish you all the very best in your ham radio activity, but the TBDXC is not the Club for you.”

I did a quick read and first thought it was about their HF marathon. But it isn't. They probabely send out this e-mail to everyone both members and participants. I'm not a member of this club and I will never be. I enjoy all kind of communication. I'm not limited to SSB and CW alone. No, the TBDXC is not a club for me. But I like their marathon. 

Luckely the e-mail contained this:

"the TBDXC as a Club is not “against” FT8. This has been said and repeated many times, but, yet again, this essential point is often misunderstood or ignored."

So if you like to participate, and like me you like to do some FT8 and other digimodes as well, you don't have to be a member of the TBDXC. 

Currently I'm 5th in the LP SSB category.

Monday, November 7, 2022

#60m Togo worked

 

Worked 5V7RU on 60m this evening. The contact was almost lost since some kind of strange broadband signal was wiping out all signals on the 60m band. Luckely a few seconds later everything came back and I received the RR73. A new one on 60m. Decided to remove my last "new one on 60m" TY0RU from my log. I'm not in their log on 60m and it seems most of the time there was a pirate active with the TY0RU call. I really don't know what fun it is to mislead other HAMs, most of us will not understand...

Sunday, November 6, 2022

DX sunday

 Terrible autumn weather today gives an opportunity to stay behind the radio the whole day. Or at least most of the time. I already noticed that there are a lot of DXpeditions on air lately. Several from DXCC I never worked before. A good test for my 4 band square halo again. But whatever the antenna is, we are all depending on good propagation of course.

First of all, several days ago I tried to work P29RO from Papua New Guinea on 40m FT8. I received him reasonable well. The miracle happened and P29RO came back on my first call with a -04dB report. But then it happened, some digital signal wiped out everything and I was not able to see anything at all. Next day I checked the online log and it seems they did receive my report, I am in the log of for 40m. Not really satisfied about this contact I decided to chase them again today. It resulted in working P29RO on 10m and 17m both in.....CW. Did you know that Papua New Guinea is one of the most linguistically diverse countries in the world. There are 839 known languages in this country.


Something else occured to me today, just a few minutes before I worked P29RO I worked 5V7RU from Togo. Just another African country I thought I had already worked. It was a pretty easy contact. But this was actually a new DXCC for me. I was not satisfied with this as well. It would be nice to work them on SSB or CW. Unfortunately I never heard them or see them spotted on the DX cluster. Worked them today on 10m and 12m with FT8.


This morning I noticed a new DXCC active on 10m FT8. It was T88WA from Palau. 10m normally should be no problem for me, their signal was strong. But no matter hw I tried I didn't get my signal through. I must have been trying for over 2 hours till their signal vanished into the noise. It puzzled me since I saw many Dutch stations made it into the log. After lunch I checked everything again and noticed my antenna switch has been into the wrong direction. I was transmitting on my inverted-V instead of the 4 element LFA. How stupid. Luckely I could just see them on 15m FT8 and after about 15 minutes I was in the log. T88WA has an realtime log search, how convenient!


The 12m band was in great shape today. I worked 3C3CA Equariotal Guinea, J28MD Djibouti and FJ/SP9FUY Saint Barthelemy Is.. Not shure if the square halo is that good, but it seems to radiate well. My signal is certainly getting there.

Finally I decided to do some SSB calling on 10m into the direction of the USA. It's what I really like. And within about 25 minutes I worked 6 stations from USA and Trinidad&Tobago.

Certainly a good DX sunday...

Tuesday, November 1, 2022

CQWW DX SSB 2022 review

Event: CQWW DX SSB contest 2022
Section: SO Low Assisted 10M
Logger: N1MM+ 
Station: Icom IC-7300 @100W
Antenna 1: 10m LFA @14m
Antenna 2: 4 band square halo @15m
Antenna 3: 2x20m inverted-V doublet @12m

Started saterdaymorning late. 10m was not open yet here. At that moment I was not shure I would do a single 10m band effort like last year. So I started on 40m and 20m. This was also a god test for the "new" square halo antenna I previously made. And I have to say...compared to the multiband vertical it is a excellent performer. It is clear to me that most of the stations I heard I could work as well. For instance KL7RA (Alaska) was barely above the noise. But I had a reply after the first call which surprised me. Same for VJ4T. Below a map made with all 1000 QSOs I made.



Oh yes, I heard the DXCC I wanted to work. V85RH and VK9C. But others did as well and I might have a chance another time. I tried a few times but the pile-up was just too large and signals too low.

Although I was active on all bands except 160m (I forgot I don't have a 160m antenna aymore) I aimed for 10m only. So most of the contest I was on 10m to work as many DXCC/stations as possible. I made quite a few runs into the direction of north america, always great to do that. Below a map from my 427 QSOs on 10m.


Surprisingly, and I believe never did this before. I worked 100 DXCC overall. Incredible to just contact so many countries in one weekend.


According to the analyzer I use I operated 30 hours and 1 minute in total. Which is a lot I think. Yet, I was not on the radio all the time. I just had breaks to drink coffee/tea and eat lunch/dinner. Besides that I had to go out with my XYL to do the necessary shopping for the week. I did have a good sleep as well. So after the contest I was tired but not really exhausted.  

I always remember some memorable moments. Like the station in Sudan (ST0HQ) that was giving me a report in dutch. Another memorabe moment was a surprise call I got on 80m by Elsie M7ELC, probabely the youngest female operator/contester in the UK. She is the daughter of fellow blogger M0YKS Simon. You can view a video about the contest featuring both here.

I also worked fellow blogger VE3VN Ron on 15m. Ron has a interesting blog full of details about the hobby. I met Ron before on 15m and never heard him on another band. He might do a single band 15m effort?

Funny is also that some stations, even when I never ever had a contact, seem to be regular readers of this blog. According to the reactions from some of these stations. If you read this it is appreciated and always nice to make the contact were ever you are. I had a lot of fun this weekend and certainly broke last years score. Surely I will be in the contest next year and will try to beat this years score.

Thursday, October 27, 2022

Upcoming CQWW DX SSB 2022


 Just download and checked my results in last years CQWW DX SSB contest. I became number one in the Netherlands on 10m single band. Not a bad result after all. If propagation is as good or better next weekend I will again try to do a 10m single band effort. However at night I will be on other bands as well if propagation on 10m is over.




There will be a lot of interesting DX stations on air in the contest. I'm particularly interested in working JD1BQP from Ogasawara, V85RH from Brunei, VK9C from Cocos Keeling Isl. and YJ0CA from Vanuatu. All announced to be active in this contest and hopefully active on 10m were I have best chances to work such DX. They would all be new DXCCs for me.

Tuesday, October 25, 2022

#60m TY0RU worked (or not?)

 I had only 10 minutes in the morning before going to the job. Just when I decided to close my station TY0RU came back for me.


But received no RR73 unfortunately. It seems they suffer from high QRM levels. 


Checking the log this afternoon says I'm not in the log on 60m. However I'm in the log on many other bands. As a matter of fact I worked them this weekend and didn't even mention it in my last post. It obviously didn't impress me, I worked 5 of the 6 bands in about 20 minutes and only 15m was worked on Sunday because I forgot to work it Saturday. I really don't like it when you don't have to try at all but work such a DXpedition at once. So, I will try again for 60m if possible, I believe the DXpedition is there till tommorow.

So different from my first QSO to Benin in 2009, it took me days and hours just to work them only on 17m.

Update 27-Okt: On a total chaos 60m band FT8 frequency I got a reply from TY0RU again this morning at 5 UTC. And again no RR73. TY0RU has a strange way of operating. 90% is calling CQ and only few QSOs are made. Besides that the number of retry when he does not receive the RR73 or the R report is only 2 times before getting back to calling CQ. It is like the operator doesn't care at all. But I  don't blame them. The DXpedition crew is probabely very tired. Since I think the DXpedtion is on it's last day I don't think I have another chance to work Benin on 60m. Ah well, who cares....

Monday, October 24, 2022

Last weekends QSOs

Luchtwachttoren (skywatchtower) 7O1 as I remembered it.

 Absolutely a interesting weekend historically and radiowise. Sunday morning after listening to the HAARP transmissions, which could not be heard here, I decided to hunt for some DX on the bands. Worked 3D2USU (Fiji) as best DX on 30m FT8. I noticed already that there was a special event going on in our country. The celebration of 60 years Cuba crisis. To the public known as the cold war weekend with the opening of several important buildings that played a role in the cold war. Some of those buiding feature a HAM radiostation as well and so it was possible to work some of those interesting locations.

Well, long time ago I had to go to school. At that time I could only get there by bicycle, very common in the Netherlands. Every day I passed an old tower overgrown with weeds and surrounded by trees. I soon learned that it had to do with the cold war. At that time we had no internet and you couldn't find much in books about it. Later I found out it was a lookout to warn when russian airplanes would come over to invade the Netherlands. It has been competely restored lately. I had no time to visit it this weekend but I might visit it somewhere in the future. Some HAMs did activate PA6KLD from the location and I was happy to work them last weekend. They were transmitting with only 3W SSB on the 40m band yet they came in 5 by 9 at my QTH which is about 25km east from the tower. 

I had some contact with PD1GAW Gerard who lives in Ulrum not far from the tower. He told me he visited it and he also gave me the frequencies to work several of the "special" locations. Thanks to that I finally worked 6 SES stations. PG60CUBA (Commandopost MBB, Grou), PC60CUBA (De IJssellinie, Olst), PA60NN (Luchtwachttoren 3T3, Nieuw-Namen), PA6KLD (Luchtwachttoren 7O1, Warfhuizen), PF60PENM (Schuilkelder, Panningen), PB60CUBA (Commandopost BB, Rijswijk). The nice thing is that I got a message from an old friend that I know from 11m years ago. In the mean time he also got his license. He told me he heard me making contact with PA60NN and was on that location. Later on he was allowed to take the mike and we had a small chat. In between the contacts I also gave some CQ on 40m in dutch so I hoped for some more SES stations that might be listening. But it was PA0FRI Frits that came back to me. Frits is well known for his incredible website full of useful info about our beautiful hobby. We talked a bit about our favorite subject which is antennas. He told me that the design of the antenna current meter was updated, I should check it out soon on his website.

Later in the afternoon/evening I decided to do some CQ calling on 10m, one of my favourite bands. With the 4 element LFA beam into the direction of north america I had a lot of fun making contacts in SSB. Hopefully the propagation will continue to be good for next weekend when the CQWW DX SSB contest is on.

Interesting read in dutch (translate if needed): https://www.luchtwachttorens.nl/

Thursday, October 20, 2022

HAARP Ghosts in the air glow

If you do some experimenting and research in this hobby I like you to point to this experiment:


Please find more info on the website:


Update Okt.23: I listened this morning but could not hear any signal. I did not check VOACAP to see if it was possible to hear Alaska. 


Wednesday, October 12, 2022

History of the 11m HAM band

  We know the 11m or the 27MHz (27-Mc) band as CB (Citizens Band) band. Some people refer to it as the "chicken" band. CB radio was very populair before everyone had a mobile phone and internet. When you search for the 11m band history you will read numerous sites about how 11m CB started in 1958 with highlights in the seventies of last century including movies like "Smokey and the bandit", "Convoy" and "Handle with care". But not many know that the 11m was a legal HAM band at least in north/south america, australia, new zealand, south africa and south-west africa from 1947-1958. 

Following several publications first experimental license was given to W6XBC (eXperimental BroadCast) in 1933, the experimental frequency was 27,1 MHz. Actually 27 MHz was considered VHF at that time. Transmissions took place from Yuma, AZ. The aim was to see if VHF was useful for remote broadcast pickups. They transmitted 1 hour per week and asked for reports. At around the same time the same frequency was used by a ship that was on arctic expedition. They used several callsigns, one of them was W10XDA.

But searching for more historical research I found that first commercial licenses were given in March 1928 to 6XAR in San Fransisco CA transmitting on 27,523 MHz, 2XBM in Water Mill NY transmitting on 27,900 MHz and 6XJ in San Diego CA transmitting on 27,900 MHz.

In the WW2 years 27MHz communication gear was used in tanks both by Germans and American armed forces. A story that can be read in several old CB magazines is about discovering 27MHz signals heard from German tanks stationed in Africa. Fiction or real, a HAM from Rhode Island recorded some strange voices he heard on the 11m band. One day he played the recording to a friend who understood German. This friend realized it was some military communictian between tanks and base stations. When the US Navy was called in they found out it were tanks from general Rommel in North-Africa. Although the signals came in almost everyday it seems best to receive was at a few square miles in the Rhode Island territory. Intelligence immidiatly took over an old farmhouse at the sweet spot en installed a few 11m receivers and German translators. Every information that was transmitted in North-Africa by the German tanks and base stations was monitored and given to the British. After the war the 27MHz was no longer in use in the military but it certainly proves that this frequency did do well in difficult circumstances.

Other users of 27MHz were doctors that used this frequency for medical uses like diathermy. This, of course, was a huge source of QRM and so the 11m was not really a populair HAM band. In 1947 the FCC allows use of the 11 meter band on a shared basis with Industrial, Scientific and Medical devices. Most HAMs operate on 11m with their 10m antenna, not really effective. In 1948 Firestone Tire Company granted experimental license W10XXD for 27.255 MHz (Ch 23) using two 3Watt transmitters. All documentation about this experiment is lost but these might be forerunners of CB radios as we know it now. 

Did you know that the US radio technical planning board proposed to lower the 10m amateur band by 1 MHz to 27-29 MHz. Although this proposal was later withdrawn, the ISM band (27,185 - 27,455 MHz) was not established until 1945, and the FCC hinted that it could be distributed to amateurs as a secondary service.

The 11m HAM band has been changed several times:

27.185-27.455MHz (March 26, 1946 to April 29, 1947) FCC Order 130-D (March 13, 1946), Federal Register Notification (11FR3158, March 26, 1946)

27.160-27.430MHz (April 30, 1947 to June 30, 1949): FCC Order 130-M (April 10, 1947), Federal Register Notice (12FR2815, April 30, 1947)

26.960-27.230 MHz (from 1 July 1949 to 10 September 1958)

The 11m HAM band was not only established in the USA. It seems 11m was also allowed in the America's (Canada, central/south America), South Africa, Southwest Africa, Australia and New Zealand.  International DX contacts were certainly possible.

But what did the HAMs do on 11m? Did they use it for nearby contacting or did they do make some DX? I searched in some old magazines to find evidence and found some remarkable things. Activity without the need for a experimental license was from 1947-1958.

-  1947 - The mountaineer amateur radio association operated W8BOK/8 at fieldday with 6 stations simultaneously. One of the stations operated "27-Mc phone".

- W3CDQ is planning a 27-Mc. 'phone-cw rig for a net composed of amateurs connected with the Central Radio Propagation Lab. (CRPL) ionosphere group.

- Several amateurradio stations researched meteorscatter on 27-Mc

- 1948 - QST June 1948 reports W9AND,  worked EL5A, OX3GE, VO4T, KH6GT, KII6BI and CXlFB. W6ZZ reports working J9AAI. All on 27-Mc.

- 1950 - The 16th ARRL International competition also counts (DX) contacts on 27-Mc.

- 1957 - The FCC announces the end of the 11m HAM band to use it for "Citizens Band"
"Save 11 meter" contests were hurriedly organized among the Hams to show the FCC that 
there really was life in the old 11 meter band. About 400 stations rose to the occasion, and 
many exotic calls were to be heard, such as CX2AY, CN8JW, XE1A, ZP5IB, VK2QL, and 
KC4AI. Unfortunately these "protests" are not enough and didn't help to convince the FCC. 

The 11m HAM band came to an end. September 11 1958 was the date that 11m would be known as "Citizens Band". In fact Al Gross W8PAL is by most seen as the man that invented CB, although the idea was already brought up in 1938 by Herbert Brooks W9SDG. His letter to the editor of QST magazine described a theoretical "Citizens Band" nearly identical to what we know today. Al Gross actually developed equipment for the UHF band since CB on an experimental basis at that time was on 250MHz and later between 460-470MHz. It looks like he had the first official CB license issued in 1948. But W2XQD was really the first one with a CB license issued February 14, 1947. It would actually take another decade before CB started on the 11m band. 



Related reading links and documentation:

Detailed information about the schooner Morrissey arctic expedition radio experiment:

https://www.rsp-italy.it/Electronics/Magazines/QST/_contents/QST%201934_12.pdf

History of the 11m band documentation:

https://ukspec.tripod.com/rf/cb/

https://www.retrocom.com/wtcollect/27_megacycle_history_in_the_u.htm

https://sites.google.com/site/cb465mhz/home

Another article I wrote about Al Gross:

https://pe4bas.blogspot.com/2014/11/historical-first-time-1944-handheld.html

Thursday, October 6, 2022

UKEICC 80m SSB contest Oktober


  Wrote about this contest before. If you are living in Europe this is one of the contests to attend when you don't have much time like me. Duration is only one hour, submission of the log within 1 hour after the contest. Results and certificate next day.

The exhange is just the 6 digit maidenhead locator.

I really don't participate in many contests anymore. Most times it is in the weekend when I want to spend time with my family. Through the work week I'm too exhausted from work to play radio in the evening. Actually I almost skipped this one but glad I did participate, I did have fun. 73..

Monday, October 3, 2022

Square halo & CG3000 autotuner combination


 

 The idea was to mount the CG3000 autotuner below the antenna to compensate for coax loss and SWR change when it is raining.

I followed several discussions about installing the tuner. A consideration was to protect the coax/12V supply from radiating. Something that is not really an issue I think because the halo design is balanced. However I did make some precautions.





Both coax and 12V supply line wound around a large ferrite should do the trick.

Since the CG3000 has the antenna connections on opposite sides I tried to make a balanced system to connect the coax from the antenna. It is not ideal, the CG3000 tuner is not really designed for this kind of use.




You can view the final result on this photo. 

Before I winched the tower in place I made shure the CG3000 was working and it did. A second test was made at half the height. On 20m the SWR was quickly 1:1. 

At full height the tuner did match 20m, 17m and 15m well. The 12m band is another story. It can't get a good match and the tuner tries to keep matching but can't find a good combination. I really don't know what is causing this. (I had the same problem with my vertical before.) I also tried it on the 10m band without any problem the tuner matches 1:1. Just for fun tried 40m and it was no problem to match, however the antenna is not designed for this band and of course it is a lot worse compared to my inverted-V.


The result of this experiment is a bit unexpected. The SWR without the tuner is not that bad, the tuner only needs to make a small correction. However it doesn't find a combination for the 12m band. Unfortunately the tuner can't be "bridged". It is not simply a matter of switch it off and use the antenna without this tuner. So, when weather permits I probabely will remove it again. The internal tuner of the IC-7300 can manage the SWR without any problem though I probabely have to live with the coax loss in the system.

Monday, September 26, 2022

CQ WW CC members are enemies of Ham Radio and Contesting?

CQ WW CC members are enemies of Ham Radio and Contesting? This sentence appears below the activity announcement of V47T (by K5ZD) on DXnews.com. I added a questionmark at the title because I think it is not a fact but more a question. DXnews.com chief editor is 4L5A Al. He wrote in very bad grammatical english about the CQWW contests exclusion of Russia en Belarus. Of course it is his opinion and luckely he is able to write freely about it. You can read about it here:


It is hard to understand especially for those that read english not as their main language. However I think he wants to tell us that he doesn't agree with the rules. Why only punish Russian en Belarussian radioamateurs? There are more unfair politics going on in the world. Think about countries like China, Iran, North Korea, Cuba and many many more....
4L5A writes: "HAM Radio need to stay away from politics.
CQ WW CC really start dirty game and their declaration that they supporting our Ukranian friends is wrong because such decision destroying relationship between people and HAM Radio was always bridge to build friendly relationship between people World Wide."

My opinion:
Well of course in other countries the politics are unfair but there is no war going on in those countries (yet). 

The CQWW contest committee has decided they want to make a point. They have a right to do so because it is their "game". If you don't like it don't participate.

Yes, HAM radio should stay away from politics. However we live in a free world and we can freely write about our opinions. Writing about opinions, political or otherwise, can be dangerous when you live in Russia/Belarus. Our opinions have a value, we should respect others opinions as well. I respect Al's opinion but my opinion is partly different.

Are the contest committee members our enemies? I'm shure the descision is made democratic probabely by voting. Some members probabely disagreed but most of the members agreed. I think this way it is a fair descision. I don't think we should call our fellow HAMs enemies, that is way too irrational.

I did not participate in the CQWW RTTY contest this year. Not because of all this but because my family is more important. What is most important in your life?

Sunday, September 18, 2022

Square halo SWR at rain and ATNO

  Reading some articles on the internet revealed that the halo (or cobwebb in general) could be sensitive for wet weather. I had to wait till we finally had some very wet weather. This evening I came back home and everything was very wet. Time to measure the SWR/resonance again.The prediction is that resonance frequency would shift downwards. The results:

12m best SWR 24.980MHz 1,1:1 R48 X3 shifted 20Khz down

15m best SWR 21.116MHz 1,8:1 R95 X0 shifted 4KHz down and SWR got worse

17m best SWR 17.840MHz 1,3:1 R60 X11 shifted 360KHz down

20m best SWR 14.272MHz 1,4:1 R60 X20 shifted 72KHz up!



The rain has a very good effect on 12m. But a dramatic effect on 17m and 15m. Strange enough best SWR on 20m shifted up. Next experiment would be installing the autotuner below the square halo to compensate for these SWR/resonance shifts. 

By the way the rain has also effect on my 4 element 10m band LFA. SWR/resonance shifts down about 100KHz.

After looking for ZL7 (Chatham Isl.) on 60m in the greyline without success this morning I decided to see if 10m would be open. At first I was already welcomed by solar panel QRM right at the bottom of 28.074 MHz the 10m FT8 frequency. Something that gets worse lately as more and more solarpanels showing up on the roofs of neighbouring homes.


Anyway turning the antenna away from the village towards Australia cleared things a little, It was just at the start of some extraordinary good propagation towards the east. Worked some Australian stations, Thailand, Egypt, Vietnam and much later Timor Leste on 28.088MHz FT8 F/H. I had to look for this country which is somewhere near Indonesia (in fact it was occupied by Indonesia till 2002). It is my first all band  ATNO of 2022.




Signal from 4W/JH2EUV was superstrong. I think a SSB QSO would certainly be possible. However the long callsign seems to give some issues in F/H mode. This is how the QSO went here:

4W/JH2EUV responded without the 4W/ prefix. Luckely JTDX still did understand it was the same station although displayed different. It responded automatically with the R -04 report. 4W/JH2EUV responded again without the 4W/ prefix and gave RR73 but also in the same sequence with another report and the complete 4W/JH4EUV call which was very confusing. Discussing the matter with DB6LL Hartmut did give me the confidence the QSO is valid. Though it seems to be a glitch in WSJT-X or in JTDX.

Sunday, August 28, 2022

Experimental setup square halo (4) - into the tower

 It has been a while. I always think that when vacation arrives I will have a ocean of time. But real life is totally different. Anyway, I had a few hours to spend today. I dismantled the 6m/4m duoband beam and installed the experimental square halo after another final check. The only thing I changed is the boom, it is the same material (glasfiber) but shortened it and taped it with black tape. 

Above a picture to compare the size of the halo with the VHF duoband beam. The halo is small, excellent for the HAM without a lot of space. Not that I have a space problem but I really find this antenna interesting to experiment with.


 The experimental halo above the 10m LFA. Really small...will it work? The vertical antenna is another experiment for CB use, it is not working like it should yet.

I observed and noted the SWR at groundlevel and up on 14m height. The resonance point and SWR will shift higher in frequency, something to consider when you would like to experiment with this antenna.

Best SWR at 1m height: 14.120 - 18.142 - 21.116 - 24.931 MHz

Best SWR at 2m height: 14.177 - 18.150 - 21.130 - 24.942 MHz

Best SWR at 14m height: 14.250 - 18.200 - 21.200 - 25 MHz

So I need the tweak 17m and 12m a bit, though SWR is good enough to transmit. But is it working? I started on 12m late in the afternoon.


Unfortunately PSK reporter is not reporting everything these days. QSOs made with HC1HC (Ecuador), ZR6JT (RSA), YV5MHX (Venezuela).

Next 15m:


QSOs made with K1JZA (USA), 4Z5UY (Israel), DJ1TO (Germany), W6NWS (USA)

Next 17m, I was worried about this band because I don't use a closed loop in the antenna. It is kind of a dipole with a parasitic element of same length of the dipole attached. Best SWR 1,7:1.

I really don't know if propagation is good or bad? But I worked VE4GV (Canada), BG0BG (China), K0IEA (USA), OZ1RH (Denmark)

And at last 20m. I did some tests comparing the 2x20 inverted-V doublet with the square halo. I have to write the halo is clearly the winner. It wins on every signal. Previously the inverted-V was the winner compared to the multiband vertical. I'm really surprised by this small antenna. It is also very quiet on receive compared to the vertical. I had only time to test 20m late in the afternoon and in the evening.

I'm not really a fan of FT8 on 20m. I didn't had much success on this band previously as it is very crowded. I was really surprised by the DX contacts I could make this evening. I worked RW4D (Russia), EA1FK (Spain), EP5CHD (Iran), N4OPI (USA), W8NET (USA), W8QZM (USA), LW4EAZ (Argentina), K4YT (USA), W7DO (USA), CP6UA (Bolivia), CX1NU (Uruquay), D2UY (Angola)

Yes, this small antenna is working well for me. Is it special? Many HAMs told me this is just an cobbweb design. Yes it is, it has almost the same size and looks like a cobbweb. But it is different since it uses full size loops instead of half wave dipoles. Except for 17m that is, I couldn't get a decent match for 17m when I use a full size loop for that band. Instead I did cut the ends of the loop and what left is a dipole with a parasitic element, strange enough it works. That's the thing with experimental antennas, it works or it doesn't. This time I was lucky.