Monday, September 25, 2023

Power from the sun causing QRM?

   Does power generating with solarpanels cause QRM? Yes and no. The strange thing is that some solar power installations/systems do radiate noise while others seem not. And of course it is not the actual solarpanel that radiates but the solarcharger, inverter and wiring do if not filtered and earthed well. Besides that many installations use so called optimizers which are known for causing a lot of noise. I will not write about the cause of this all. Only about my own experiences and the things I did to prevent QRM/noise from a solar generating installation at my own home.

Buying a solar system

The dutch goverment wants to have as much "green" energy as possible of course, it will be the same in other countries I guess. To support home owners to buy solar installations for private use we can now buy these VAT free. And of course if you're able to install these yourself it is possible to buy a reasonable installation for about 2000 euro. With the current and rising electricity prices and the increasing amount of electrical things at home this is of course very interesting. I really don't care about the impact on the environment in which I do not believe. See my post here: So we decided to order an installion of 8 solarpanels which we thought to mount on top of our glasshouse. 


Because I wanted to do all installation myself it was a great opportunity to see what I could do to prevent QRM. The inverter is placed behind the wall of the glasshouse on just about 10m from my antennas. I already have much noise from neighbours surrounding solarpanels (they use optimizers) so I really didn't want to have a increased noise from my own installation.

The first challenge was how to mount the panels on the glass. Normally solarpanels are mounted on a roof with tiles. I invented simple aluminium frames on which I could mount the aluminium  mounting rails that were supplied with the panels. I could mount 4 panels per frame. The total weight of one frame with panels would be approx. 100kg. The next challenge was how to mount everything on the glasshouse without breaking the glass. The idea: place the frames on the lower end of the "roof", mount the panels on the lowest rail and hoist the frame up the "roof" with ropes. Luckely the glasshouse consists of aluminium profiles which hold the glass plates sealed with a kind of rubber strip on top. The frames could slide over the rubber strip without breaking the glass. Well, in the end I managed to break four glass plates, but they were easily replaced. Luckely I was able to hoist the frames myself. The frames are secured on top of the brick wall. The lower end of the frames is not yet secured, I have to invent something for that since I cannot secure it to rubber, glass or the aluminium profiles.

Preventing QRM/noise

Time to install the wiring. Of course I already got information how prevent radiation from the system as good as possible. The things I did:

- Prevent a loop with the DC cable. The panels are connected in series. The positive and negative wire are running back as close as possible to the connecting wires in between the panels.

Alu duct running up the wall

- The positive and negative DC wires are running through the center of the 8 panels in between the two frames up to the wall. I mounted the inverter on the other side of the wall. I twisted the wires the whole length to the inverter.

- Where possible I run the twisted DC cable through aluminium earthed ducts. Both frames and  the solarpanel(frames) are earthed to the mains earth.

Large ferrites

- Ferrite material #31 clamps are placed on the start of the positive and negative returning DC cables. Ferrite clamps also placed at the point were cables are going up and on top of the wall.

- Ferrite FT240 #31 torroids placed just below the inverter at the DC wires and the AC cable.

So far I didn't notice any increase of noise on any of our hamradio bands. 

For free

Free energy from the sun. Like it or not but it seems to work well. And it is possible to have it without QRM/noise if you ensure a good installation.

Unfortunately we didn't have much sun last week. But at least 27 kWh in just 6 days. Enough to run at least my radios/computers for free.

Friday, September 22, 2023

Visiting satellite communication ground station

 My dad and I visited the Inmarsat sat communication groundstation last weekend. I has been very interesting. We made some nice photos I would like to share here on my blog. Although not far from my dad his home I never really been in that area. Normally this terrain is closed for public of course. But last weekend there was an open day because of  the 50 years anniversary. Not on the photos (just forgot) was the amateurradio station with the call PA50B. I met some HAMs that also visited the station.

We were not allowed to make photos inside the buildings. But I couldn't resist to photograph this. It is a ESD test device to verify you are entering an important sensitive electronics containing building discharged of any build up static electricity.

In realize now that I the amateurradio station is at the left of the sat dishes. Right of the green building.

I'm shure some amateurradio sat operators would love to get this scrap...

My dad in comparisation to one of the "ears"

Well it was an interesting visit. I was not aware that they not only provide emergency communication for ships but also internet for several ships and planes. At this moment there is a lawsuit going on between inmarsat and the national telecom operator who wants to have more bandwidth for their 5G system. It would be a pity to lose such a life saving communication station because the telecom providers want to believe people want faster internet on their phones...

Tuesday, September 12, 2023

#6m #4m ES-season 2023 review

 This is my review of the 2023 ES-season I enjoyed on 6m and 4m. Actually I was too late mounting the antenna in the tower this year (18th of may). Good tropo propagation on 6m already appeared in April. So I missed some great DX. But I can't complain since at least 12 new band DXCC were worked on 6m. And I was able to work 2 new band DXCC on 4m which is of course much more difficult.

27-May: I worked both LU3CQ and CX1VH within minutes. Argentina and Uruquay are the first two new 6m DXCC this year. Both are confirmed with LotW and eQSL.

29-May: Best time for the south Americas it seems. I worked ZP5DBC Paraquay on 6m. QSO is confirmed by with LotW.

5-June: Expected since I already noticed that Switzerland has 4m access now. So I worked HB9OAB for a new DXCC on this band. First new 4m DXCC this year and confirmed by eQSL and LotW.

9-June: Several sources did note that D2UY from Angola could be heard on 6m with excellent signals. And yes, I heard D2UY several times before this date. But then, finally, after a lot of effort I was able to make the QSO. The QSO is not yet confirmed however. 

8P2K was also worked on the same date. No luck in previous years but this time I finally made it. QSO is confirmed by LotW.

30-June: Heard in 2021 but not in 2022. This year I was able to work PJ2BR from Curacao. QSO confirmed with LotW and eQSL.

1-July: Worked 4L7T from Georgia on 6m. Not confirmed yet. His QRZ page says "LotW coming soon". In the mean time you have to pay $$ for QSL which I will not do.

1-July: Propagation was excellent into the east direction. Suddenly there was VU2NKS from India which I worked for a new one on 6m. QSO confirmed with LotW and eQSL.

1-July: Not only on the 6m band propagation was very good this day, 4m was in good shape as well. Surprisingly I worked OD5KU and OD5ET from Lebanon on the 4m band. OD5KU confirmed the QSO on LotW.

1-July: This was my lucky day since I worked another new one on 6m. Actually I thought I already worked Guernsey C.I. but after some investigation it looks like I did not. So I worked GU4XGU. The QSO is confirmed by LotW.

9-July: No luck last year, but this year I was lucky. V51WW from Namibia was worked quite easily. No confirmation yet.

25-July: It seems that south Africa could be worked with strong signals already in April. Unfortunately I had no antenna up at the time so I missed that. I saw ZS many times this year but was unable to get one in my log. But this day I was lucky and worked ZS6NK. Since I didn't get any 73 I was not shure I was in the log. But contacting Paul via KST chat he confirmed I was in the log and he would be confirming by LotW. Certainly that happened to be the case.

Looks like Paul is also active with 6m EME (Earth Moon Earth), something I would love to do some time. However I think you need at least a large antenna and a lot of power. 

Then we went into August. I know from previous years that DX can still be worked but less frequent. This year there was no big opening to the USA surprisingly. I worked USA west and east coast and also Canada this year. But only a few stations and it was not like in 2021/2022 when we had days with such strong propagation you could not find an empty spot in the waterfall.

8-August: Other stations in my neighbourhood already worked this station in April/May this year. I missed that but was lucky at this day. I worked SU1SK from Egypt for the last new 6m band DXCC this year so far. QSO not yet confirmed.

This year, against all odds, I decided to keep my 6m/4m duoband beam in the tower for the winter season. This because of expected F2 propagation due to the solar maximum at the end of the year. I really don't know what to expect. Some OMs tell us the great stories from the past. It seems that the propagation I have experienced the last couple of years is nothing compared to good 6m F2 propagation. Well, we will see...

(2-Okt: updated adding 8P2K)