Friday, 16 June 2017

The PL259 myth

You often read or hear that every PL259 connector on your coax adds 0,5dB loss. This might be the truth on UHF and higher. But on HF/VHF that's not the case.

Recently I was thinking about the 50m Aircell7 coax I run to my antenna now through a homemade disconnect/patch panel. So, this coaxcable to my HF antenna contains 4 PL259 connectors and a female/female barrel to connect the 2 pieces. 50m Aircell7 has a loss of about 1,8dB on 28MHz and 2,4dB on 50MHz. I've no interest in VHF/UHF so leave that out.

At the new antennamast I want to have another patchpanel at the bottom of the mast like I had before in my previous QTH. I want to add some lightning protectors and a galvanic isolation transformer for the highest (HF) antenna in my mast. Now I was afraid all the PL259 connectors would add a significant loss to my transmission line. But after all I think it is not that much.

Steve Katz, WB2WIK/6 demonstrated at the Dayton Hamvention in 1985 that the loss in an 83-1SP PL-259 connector averages .0435 dB per connector at 28 MHz.
The primary difference between a "zero loss" PL-259 installation and a lossy one is how the connector is installed


PE4BAS experimental test site
However, I'm not a believer. I like to test this out. Although I haven't any high sensitive equipment, only my trusty MFJ-259B. Is the PL259 loss a myth or can I bust this? I did some test this evening and made some interesting discoveries.

My not-so-scientific test setup: MFJ-259B, 2 pieces of 10m long Aircell7 coax laid down in the too long grass with PL259 connectors both sides. Only soldered at the center. Braid is screwed into the connector when I assembled it in 2005.

10m Aircell7 has a calculated loss of 0,36dB. 2 PL connectors have a calculated loss of 0,087dB = 0,3687dB (0,37dB including the female/female barrel connector). Total loss of the 2 pieces calculated 0,74dB. Lets see:

Left: 1 Piece of coax - Right 2 Pieces connected
Of course the MFJ-259 is not very accurate and has losses itself. However, this is not a bad result.
Ready to do a practical real life connector test...

13 connectors in total
I connected the 2 pieces of coax with as much connectors and connecting barrels as I had. Besides 2 times PL259 I added 11 connectors. This should add a calculated loss of about 0,4785 dB (0,48dB). But in real life it only add 0,1dB.


Another test....add 4 times a 90 degree connector. Now this is going to be serious!!! There could be a faulty connector. So test just one of them:


Still higher loss. 1 90 degree connector 0,7dB loss,  The 90 degree corner does probabely affect the impedance of 50 Ohm?

PE1BVQ Hans is always searching for silverplated old PL (and other) connectors at radio rallies. Preferable the original amphenol ones. I asked him why, he says they are the best, others can add a lot of loss in your system. Could that be true? Or is this another myth that's going to be busted?

Let's see:


I changed the 90 degree connector for a silverplated original Amphenol one. Gone is the loss! How strange is that?

Well, of course I don't use any superduper sensitive low loss equipment but it shows that there can be a difference in connectors. As long as the connectors are mounted in a straight line it hardly gives any loss. Very important of course is a good soldering connection between the coax and the PL connector.

A few tips:

* Solder both core and braid. Best way in my opinion is how it is done by K3LR.
* Keep connectors clean so they can make a good lossless connection
* Tighten them well. I checked that as well this evening, a loose connector gives about 1dB or more loss and propabely a lot of unwanted RF around the loose connection!
* Prefer silverplated (Amphenol) connectors, they probabely are the best you can get.
* Amphenol too expensive? Look for them on radio rallies. I payed about 50 cents for the 90 degree connector.

Thursday, 8 June 2017

The 6m band holy grail

For us here in Europe the holy grail of the 6m band would be working Japan on 50MHz. There are several thoughts about how a distance like this can happen. But at least you need ES propagation or Sporadic E just what you like to call it. This happens only a few times a year and only at a small timeslot around 9 UTC it is possible to hear and transmit your signal to Japan. There are years that this doesn't even happen at all. With JT65/JT9 mode it is a lot easier to spot Japan, but a QSO is still difficult as the JT modes are just too slow. However I managed to spot a few Japanese, best distance was 9125km spotted JR2WYD. My neighbour PA0O even worked Korea on 6m for the first time in his 30 years DXing on the 6m band!  I was surprised I spotted DS4EOI from Korea today at -16dB myself, that's a great signal on JT65! Think of my antenna system which consists of my Watson W2000 triband at only 6m height and 3 pieces on Aircell7 coax all connected through PL connectors. Crappy 6m setup you would say. Imagine what could happen if I had my mast and 5 element 6m yagi up!



Another spot intrigues me. N6ML at that time of the day. Strange propagation....


Some 6m experiments

Did some experiments last evening. On 6m that was, a band that is only really open during the so called ES season. And wow, it is open for shure. Last couple of years it was not that good I remember, but this year it is very good.

First experiment was some CQ calling on CW and view if it was received. Wow, it was received. Did not expect that. A easy view if propagation is good and in what direction.

Second was to call CQ on USB, see if someone would come back to my tiny signal. Using about 50W this time on my 6m heigh W2000 triband antenna. And yes, they came back....a complete pile-up. Everyone wants to talk to me....feel like a important DXCC ;-)

Last experiment was to work DX on JT65, but although Brazil was received (-10dB!) it is not a easy task to work DX with my setup. However I know it is possible and just a matter of perseverance...


No real DX QSO, but I was spotted in the USA by WD8JJA with -18dB. Theoretically a QSO would have been possible... I used about 30W.

Wednesday, 7 June 2017

Digital revolution or evolution (VE7SL)

Don't do this very often. But this post is very interesting and intriguing. I've been thinking about this to write here in my blog but Steve VE7SL wrote about it already.

In case you missed it:

http://ve7sl.blogspot.nl/2017/06/digital-revolution-or-evolution.html

Monday, 5 June 2017

Dutch Kingdom Contest 2017 review

Event: Dutch Kingdom Contest 2017
Section: LOW power SSB (A1SSB)
Logger: N1MM+ latest version
Station: Icom IC-706MK2G at 100W
Antenna 1: Coppertape vertical (7,1m)  @9m agl
Antenna 2: Watson W2000 for 6m @6m agl

Just looking back at my last year effort. I had the feeling propagation was even worse. I started Saturday evening and there were only few on the 20m and 40m bands. However I made some DX, don't ask me how it was possible...Then Sunday morning, I woke up very early and started on 40m....an empty band. Really nothing could be heard except for some CW at the low part and of course the ever present JT signals on 7076 the rest was noise only. 20m band was empty as well, other bands are normally not open early in the morning. So, no one came back after calling CQ on both bands for 15 minutes and I decided to do some 60m JT65 operating instead, that went well although signals were not that strong. Later in the morning 40m and 20m still almost dead, only a few stations in the background. 6m seems to be opening and again decided to do some JT65 mode there to wait for better propagation. Then the family woke up and had to do other things. Just before the afternoon had some minutes to try again. 6m and 10m was much better and although most stations did not participate in the contest I still got some stations back to me as apparently there was another contest going on as well. Had to stop contesting before noon. Unfortenately I didn't work any known expat (extra points) like I did in previous years. I did work SO8FH (PA0F) Frits on 6m but he was not in the contest as he told me so I guess he is not known at the DKC organisation for extra points. On 10m I spoke TK/PH2A, not shure if he counts for extra points as well. In the end the 6m band saved the contest a bit, actually it was my best band after all. Total amount of QSOs is higher compared to last year. I defend my first place though I'm not shure I will be able to maintain.....time will tell.

Combined results map

Friday, 2 June 2017

6m band conditions - Reminder DKC contest this weekend! - Another record!


Above the 6m band yesterday evening. Heard HI3T several times but was unable to make a QSO. A directional antenna would be great but haven't got it yet and still do with the W2000 vertical. Neighbour station Jaap PA0O did make it to Japan yesterday morning

Just to remind you all that the Dutch Kingdom Contest is this weekend. Sections and rules here. Keep in mind that the IARU CW fieldday is on also and we don't want to interfere. The contest is from 15:00-15:00 UTC (24h).

My effort in the CQWW CW contest last year did pay off. It seems I have luck chasing Netherlands records. A lot of fun...

Thursday, 1 June 2017

GPS timing for JT modes

After my last post about the Denmark holiday experimental radio activity I got a lot of e-mail if the GPS timing I wanted to make is already working. Strange not many amateurs use GPS timing instead of a NTP internet timing. It is very common with for example the WSPR kits from Hans Summers G0UPL. If you are in the field without a internet connection GPS might do the trick and you get some extras as well. I know many blog readers are eagerly waiting for this post I even got a e-mail from HS0ZBS Kurt who only has a internet connection through his phone. He likes JT modes but has to pay lots of money only to keep his laptop on time, a GPS timing would be perfect for him.

So, I bought a cheap small bluetooth keyring GPS receiver for this task. I researched the minimum requirements for this task and think it is important to have a Sirf3 GPS module chip inside the receiver to have best receiving capabilities. I payed 25 euro for it but I'm certain there are cheaper ones with or without bluetooth. For instance this one on Aliexpress for 15 USD only. Unfortenately I had bad luck as the Li-ion 3,7V 450mAh battery inside was broken. I considered to send it back but that would mean it would take several more weeks to continue experimenting. So I decided to hook it up to an old tablet battery I had on my desk. The GPS was starting now and made connection with sats and with my laptop. Unfortenately my old Windows XP laptop didn't assign COM ports to the bluetooth communication ports automatically, but I solved that manually. Still it didn't show location and didn't sync time. Even a test tool couldn't make a connection. Finally as a last solution I restarted the computer and magically the GPS coms came alive...

I use a time sync program from IZ2BKT which is doing both synchronisation via internet and GPS. The extras and proof it is working are the exact coordinates and WW locator you are in together with the altitude. This is great info for those that are working in fieldday, RaDAR or portable configuration.


Friday, 26 May 2017

Prize giving and Jutberg 2017 radio rally

I had the opportunity to do the prize giving myself as Hans PE1BVQ did invite me to travel with him to the Jutberg radio rally. Hans did win the book "The complete DXer" when he finally found my location in the little give away contest I did last month. We had a great time at the radio rally searching for items we can use in our experiments and during the travel we talked a lot about the hobby and other things. If I never started this blog back in 2008 I would never have met Hans I guess. One of the great things that happened through writing about my radio experiments and adventures on the internet.

I made a small video with a impression of the radio rally and included some photos from items I found interesting.



Tuesday, 16 May 2017

Some solutions...

Sorry for not updating the blog for a few weeks. Other things besides the hobby occupied my time. Not that I was completely absent from the hobby. I removed the 10m HB9CV again and it was replaced with the Watson W2000 6/2/70 antenna for 6m mainly. Unfortanely so far I did not see much sporadic E coming this way. Although I was spotted in the Ukraine when the band seems to be closed! I've also been on MSK144 but only spotted a German and a English station. I probabely expect too much from this mode or I have to wait for ES or meteors.

Some solutions came up for the problems I encountered when operating portable in Denmark. First of all one of my colleagues on the job modified my tripod to mount the MP-1 directly on top just like the tripods superantenna is selling. Normally a tripod is provided with a plastic mount on which you can screw your camera, you can turn your camera then in several angles. Nice, but not strong enough to hold a long antenna in the wind. Now I just have a single 1/4" bolt on top of the tripod...

Another problem was how to handle a QSO on JT65/JT9 digimode with a extra prefix? The software is limited to just your call and when you're in another country you have a problem in handling a complete QSO as it just ignores for example OZ/. The solution came last week in a QSO with 5Z4/DL2RMC from Kenya. As you can see in the picture I tried to send 5Z4/DL2RMC TNX 73 but the software/mode is limited, confused as I was I clicked the wrong report message and quickly changed that to DL2RMC PE4BAS RR73. DL2RMC came back with his full call. So I assume not completely correct but when abroad you better send CQ OZ/PE4BAS (no locator as that is too long), in response there is no other possebility to send only your call without the extra prefix. For the opposite station it is important to finish with the full call like DE OZ/PE4BAS 73. Will think of that next time...

At the 4th day we were in Denmark the laptop lost his internet connection and since the internal clock from this old laptop has a 10 sec. delay every 5 minutes it completely lost it's time resulting in no decodes on WSPR anymore. I've thinking about this and this is also a problem when you want to do WSPR or JT modes in the field without a internet connection. As known these modes need exact timing from a highly accurate clock. So I was thinking about a small USB or bluetooth GPS receiver for this task. Together with IZ2BKT's BktTimeSync it should work. I will order a cheap keyring GPS receiver to test if it does and report about this later.


I finally combined PSK, JT and SSB logs and come till a total of 10 QSO from Denmark. That doesn't sound much but considering the setup and my holiday style operating I think it is well done.


Sunday, 30 April 2017

While we were away...

While we were in Denmark last week this huge windmill was build en visible from our Garden. So we went out to take a look nearby. This windmill is 200m high and supposed to be the largest one in our country. Several of these will be build in the Eemshaven near my QTH. This one can make 4,5MW of energy and produce for 5000 households.

Imagine in the last century and even before the highest building in our province was the Martinitower in Groningen city. It is (only) 100m high. This windmill is twice the height of the tower.

Look at the size of the large crane and truck at the feet of the mill. They look like tiny toys...




A view from the back of our garden...in the center you see the windmill...

Friday, 28 April 2017

We have a winner...

We finally have a winner. It is PE1BVQ Hans who came with the final location. Was it hard to find me? It seems so because there were no other right answers. Actually not many seem to have a interest in a book about DX? Hans, you will get the book and it is interesting for shure. Well, to find me was not that hard. Even without a radio it would be possible. Just check the activity list at wsprnet.org and find me. Then it is just a matter of writing my call in the database to find the locator. The hard part was the exact name of the location. If you think logical the best guess was somewhere on a vacation park which is as far as I know the only one in this square. 3 options were right. The exact location was Selkaer Molle but Selkaer or Glesborg would be right also.

Well I ended transmissions, the whole station is packed again. We will go home tomorrow and leave early. It was a great vacation. Hobby wise I learned a lot again. The superantenna MP-1 tripped over by the wind again and I really find another way to connect the antenna to the tripod as it cracked again. I know the tripod is made for a camera and not for a (heavy) antenna. I've been active on 20,30 and 40m and made some QSOs in SSB, JT65 and JT9. Only one QSO with the homeland.PD0ME Margienus was the lucky one. PB7Z and PA4GB almost made it but were unable to pick my weak signal out of the noise.


At a certain time on 40m I had a small pile-up ;-)....
Well, look at the picture. JTDX still is amazing. 2 decodes on the same (722Hz) frequency. I worked M0PXS by the way...


Wednesday, 26 April 2017

OZ/PE4BAS update

My separate shack on the left!!!
A small update from mu vacation qth in Denmark. I'm surprised there is still no definitive winner in de give away contest. PE1BVQ is close but does miss the QTH name. Just 2 tips: I'm not in the center of the locator square and of course I'm on a holiday park.

Till now I've been on 30m and 20m band in PSK, JT65, JT9 and SSB. So far made only 3 QSO. In PSK seems to be difficult, I don't know why? I have made many calls and am not spotted anywhere? WSPR is a great success. See the map.Will be switching to 40m soon...




Sunday, 23 April 2017

??/PE4BAS/P from ? (give-away contest)

At the time I write this I'm somewhere on the bands. I'm portable but will not tell my location or exact call. I don't tell which band or mode I will transmit. Like last year I would like to know if you can find me? Tell me:

- What call I'm using
- Which country I am in
- my exact location (locator and nearby town)




Please respond with a comment below this post. The first one that has a correct answer will get the book
"The complete DX'er" from Bob W9KNI send to the adres I will find on QRZ.com.
Since I will not only use WSPR but also other (digi) modes this will not be easy I guess. I'm curious if someone will find me during the week.


Thursday, 20 April 2017

More portable tests

Had one evening to do final tests. I think all the radio gear is still too heavy. I use 8 Mtr Aircell7 coax and a small piece of 3 Mtr RG58 with a home made window "throughput". The Aircell is heavier then RG58 but has considerable less loss, it is a choice. I still think the VOX modem can be build smaller and another heavy weight is the SWR meter. I don't put the antennas in the backpack as it will travel in a corner of the cars trunk.





Anyway, had a few hours to test the superantenna MP-1 for the upcoming portable event. This antenna is small and doesn't weight much. It is not too tall so it will not be visible by others when standing on a side of a house. Didn't change much on the antenna but last year it felt on the ground and I had to repair the telescopic part again which is in my opinion the weakest part of the whole antenna. I decided to make a spare telescope antenna and take it with me...however I didn't have the time to actually test this "new" homemade part.



I chose the 40m band and build the antenna in the garden just beneath my shack. Complete setup takes about 5 minutes. It includes the tripod, antenna and the 4 wire radials. The tripod is held firmly on the ground by extra guylines and tent pegs. This tripod is not suitable for use on concrete or rocky soil as it is just too light and the antenna and tripod will be blown over by the wind.




After some tweaking the SWR was almost perfect. Unfortenately on 40m bandwidth with SWR beneath 1:2 is only 100 KHz. Doesn't matter for me, tweaking is not difficult.

Great, ready to go.....forgot something....





Had to do some tests of course...some PSK31/63 tests didn't work. Don't know if it is the modulation on FLdigi or just the QRM on the receiving stations site. However JTDX did a great job! It does surprisingly well on my old Windows XP laptop.


First station received was JF3VAX from Japan. Both antenna and software still are amazing!
Made only one QSO with RN3ZRD from european russia and got a -21dB report. I was TXing with 5W.


QSL

A QSL is the final courtesy of a QSO. I know as that is one of my own rules. So I have to apologize. It took almost a half year since I updated clublog and  LoTW. I did update eQSL but didn't look after the QSL received after that. QSL (confirmation of a contact) is a important part of our radio hobby but all the administration that comes with it does take time and for many this is not a hobby within the radio hobby. Anyway, I once again decided to take another batch of my received paper QSL cards to the garbage. I'm so sorry but I think the paper QSL era is really over, it is not of this time anymore and I think it will disappear in the future. It's my opinion and I'm not afraid to write it down here. I guess there are a lot of HAM radio operators that will not agree! However as long as the paper QSL exists I will follow the "QSL code of conduct". Of course I did not throw away everything....I kept the QSL cards from exotic stations and those that I want to remember because they have a personal meaning for me. I like QSL cards that you can tell a story about...

Here are some of those QSL cards I kept and will not throw away:


AH0K Mariana Islands worked 26 Oct 2014 on 10m SSB. My first QSO with this exotic Island



BW2/JP1RIW Taiwan worked 30 March 2013 on 15m SSB still my only QSO with Taiwan


EI9KC Ark from Ireland worked 6 Jan 2016 on 80m SSB in one of the UK-EI contests. Ark has his own interesting blog. Although it has been a while ago since he wrote something there.


FT4TA Tromelin Island worked 9 November 2014 on 10m SSB. Not always easy to break pile-ups but this one was easy for me.


KH2F Guam Island worked 19 Oct. 2013 20m RTTY. Another exotic location at the other side of the world for me.


OH2YOTA Finland worked 18 Jul. 2014 40/20m SSB. Youngsters On The Air activation. Story behind this QSL can be read here.


OQ5M Belgium worked 15 dec 2013 on 10m SSB. I worked Franki on backscatter. Actually normal skip to Belgium occurs only in summer if you're lucky, it is just too nearby. Story and video can be found here. Frank has a nice blog but has a busy family live just like me and not much time left for radio.


P40BC Aruba worked 27 Sept 2015 on 15m RTTY. A happy island for shure but not heard very often. This contact was made in a contest. Most of the small islands seems to have contest stations that you can rent for a activation. It's someones bussines...


LA/PA3FYG/P SOTA LA/RL-061 Aslandsnuten Norway worked 16 Jul 2014 on 40m SSB. Can you see yourself sitting on a mountain top making contacts? Well Hans does, read the story behind the QSL from this QSO here.


PA45FREEDOM worked 16 May 2015 on 40m SSB. With a group of friends across the Netherlands activating 8 different stations in the month of may 2015. It was great to participate. Read my story here.


PA61ZRK worked 8 Feb. 2014 on 40m SSB. On front of the QSL is the transmitter that was used for emergency traffic when there was the big flood disaster in 1953.

PB7Z worked 8/9 Feb 2014 on 160/80/20 SSB. But worked Bernard on almost all bands. We are radio friends since a long time. I think the first time I talked to him was around 1990 on the 11m band. We are both HAM radio operators and stil enjoy the hobby. I meet him a lot in contests. Another big hobby of him are husky dogs and fishing. Bernard lives about 50km south of my QTH.

PB14MILL worked 10 May 2014 (national mill day) on 40m SSB. Another project from PB7Z and friends. They "activate" this mill every year via HAM radio. I want to do a similair project in the future if time allows as I live close to a polder mill which has never been activated before.


PE1BVQ worked 9 Sept. 2014 on 80m SSB in the PA-beker contest. Actually I know Hans from his comments on my blog. We met a few times personally and went to a radio rally with him. We are planning to do that again this year. Hans is truly my most loyal blog reader!


PF5T worked 13 Feb 2016 in the PACC contest on 80m SSB. Frank is a follower of my blog and does his comment most time with a e-mail. Frank is doing QRP most of the time and has a busy family live as well.


S9TF Principe Island worked 8 Feb 2014 on 10m SSB. One of those exotic islands you never hear on the bands. My first and only contact. It will take some years before we can hear such DX again on the 10m band.


UX5UO Ukraine worked 21 Okt. 2013 on 15m SSB. I worked Gennady a couple of times now. It is my QSL printer and shure recognizes you on air if you did business with him. Nice to say hello and thank you personally to him over the radio.


VK0EK Heard Island worked 7 Apr 2017 on 40m CW. Heard Island on of the most remote places on earth. It took the DXpedition 2 weeks to get there from south africa. I took me several evenings before I was in the log with a error, it was corrected within a day. Read my story here.

VK9XSP Christmas Island worked 27 okt 2014 on 10m SSB. I remember that it was one of my lucky QSOs. Pointing the antenna, made the call, made the QSO.


ZD8O Ascension Island worked 29 Okt 2011. Another exotic island which is not heard very often on the radio. Can't remember the QSO well but it is still a nice card from a far away place.

Well, I hope you readers enjoyed the stories and background of some of my QSL cards. I have some more but for now this is it. 30-20 years ago I stored everything in maps. I was still on 11m CB radio and have confirmation of about 240 DXCC there. On CB you haven't got QSL bureaus and need to send everything by post which makes QSLs more valuable of course. I have lots of QSL cards from that time that are more valuable to me then any of my HAM radio QSL cards. Sometimes when I look through those old maps I really get a warm feeling and wish the 11m CB DX bands could be a legal part of our radio experimentation as well. Time will tell...