Tropo on 2m

Yesterday we had some tropo propagation on 2m.
Stations from most of Northern Europe were received, as well as a Southern France station in Provence.
In the evening the best signal was EA2XR in IN83ki (about 1750km), though I did not have enough power to work that one, and I just saw it after the fact, anyway.
The PSK Reporter map of stations received looks good.

Update 0855Z : 0739Z R5WM in KO72qi ( Kursk - about 1550km)


New Satellite With Amateur Radio Transponder Launched

The Es'hail 2 satellite has been launched and is going into geostationary orbit. This satellite has TV transponders, and something new for radio amateurs : a 2400MHz to 10GHz transponder in geostationary orbit.
The coverage should be all of Europe and Africa, to the East into India, and to the West a tiny bit of Brazil. I assume that some testing will be going on before the transponders go online, but this is an exciting time for radio amateurs interested in satellite communication.

For reception a 1m (3ft) dish with a PLL controlled LNB, as well as a receiver around 700MHz should be sufficient to hear the transponder on 10GHz, even if the frequency stability is probably not very good.
That would be my first step in amateur geostationary satellite communication.
Now I have to find a PLL-LNB.


VP8 on a "Dead Band"

This afternoon provided a new DXCC for me, since I moved back to Denmark.
I was monitoring 10m FT8, and suddenly VP8LP (Falkland Islands)showed up on the screen, calling CQ. I did not even get the linear started
A single call from me was sufficient, and we exchanged -05/-09dB reports.
Now LW5DD is on ... starting the linear . LW5DD is long gone, but I called CQ for a while with no reply.
Earlier I could read ZS and 3B9 on 10m.
In any case, right now at the bottom of the solar cycle "10m is dead" .... No, not really.

Update : 2m Horizontal

I went up to check the antenna system.
It looks like the cables to the preamplifier and between the preamp and antenna are fine, leaving a fault in the antenna.
I suspect corrosion in the antenna itself, and the fact that the construction of the Big Wheel antenna is not particularly water proof.
The "VSWR" at the radio shack shows just under 2:1, so I think that I will leave the antenna up for the winter, and just use the PA with reduced power into the system for the time being.

This is, of course, not ideal, but I am not going to take he system down right now, just before the winter with its super antenna weather (You know, rain, snow, ice, wind etc).

It is a compromise, I know, but better than having no antenna at all during the winter season. After all, I did hear English stations with this system last night, so it is functioning, after a fashion.

Come spring, a small beam with a rotator is in the planning.


Fault in my 2m Horizontal Antenna

It looks like I have a fault in my antenna system for the 2m Big Wheel antenna.
The PA suddenly started acting up when I used the HF Vox with FT8 on 2m. The antenna was tested at the radio end of the cable, and suddenly the SWR is around 2.5:1 over the whole band.
It is dark and rainy outside, so a check will have to wait until tomorrow. Climbing in on a wet ladder and in a wet tree is no fun.
Pity, because I was reading English stations on FT8 tonight, but no use ...

Update : Checked if the connector indoors was faulty, and used the opportunity to change it from a PL-259 to an N connector. I am expecting the new PA this week, so better be prepared.
Tomorrow I will check the outdoor part of the system, hoping it is easy to find and correct.


VHF-UHF FM station at OZ9QV

For my main activity on 2m FM I use a pure 2m FM transceiver, no dual- or multi-band TRX there.
My antenna is the Diamond V-2000 capable of operating on 6m, 2m and 70cm.Until recently I used a cable running into my attic space, then extended down to the living room.
Having two extra junctions in the cable is bound to increase losses in the system, so I decided to lead the cable directly into the ground floor, eliminating the extra junctions. Just a single length of about 25m type 400 cable with a PL connector at the antenna, and N-connector in the living room.
Add a triplexer and 2m, 70cm and 6m can be connected to 3 different transceivers :
6m : My old IC-575 6/10m TRX for 6m. Only 10 W, but I do have a 100-150W PA lying around.
2m : A 70W 2m FM TRX.
70cm : My FT-8900 running on 2 frequencies on 70cm.

The results are encouraging . The RX, as well as TX performance of the system has improved audibly on 2m and 70cm. 6m was not tested. I estimate an improvement of 2-3 dB on he 2m part, and probably a bit more on the 70cm part.

Now I think of possible improvements.

Power capability :
The limit on power capabilities are with the antenna itself. The spec in the table at from Wimo's website says max 150W. The triplexer is somewhat better, specified for 800W PEP on 6m and 2m, and 500W on 70cm. I estimate from this that the FM capability for the triplexer is around 250/250/200W, so the limit is at the antenna.

Receiver sensitivity :
On 6m there is no problem at all. The antenna noise is clearly audible on the IC-575.
On 2m the loss in the cable/triplexer is probably low enough to be acceptable.
On 70cm, however, the cable/triplexer loss is probably around 3dB, reducing the RX sensitivity of the total system considerably. In any case more than 3dB, probably a deterioration of about 5dB when compared to an "ideal" system.

Conclusion :
There is room for improvement all around. on all 3 bands, though mostly on 70cm. This would mean moving the triplexer up into the mast, near the antenna. Oops, then we need more cables, but that is acceptable to me. The preamp(s) can then be mounted near the antenna, improving the system sensitivity (noise figure), especially on 70cm.Now, the antenna is located near my (big) shed, so it should be possible to mount linear amplifier(s) near the antenna, again with 70cm being the best improvement. For 6 and 2 the linears would probably be fine mounted in the shack.

I do have a set of German preamplifiers for 2m and 70cm, and even one for 6m, with noise figures around 0.6 - 1dB. This I consider sufficient for use with FM, for mostly local, or, as I call it, "local tropo" (distances within 250km from me). I know, with the right conditions this could be much more.

This is my idea for an optimized use of my antenna/linear/TRX combinations.

Further, I have a low placed antenna for 2m/70cm with a dual band TRX, for monitoring a local cross band repeater.

Additional :
I love to monitor several frequencies simultaneously, so, in addition to this, I would like to extend the receive side of the bands to include more receivers.
I see two options, either, a separate receive antenna with a preamp, and separate cable with power splitters going to different receivers, or, making switch boxes on each of the transceivers, each with a receive preamp and a power splitter for the receive signals.

For now, I monitor one frequency on 6m, 2 on 2m, and 3 on 70cm with the antenna system just described. Of course, when transmitting on one band, all other reception on that band is out of the question .... or is it? That is a story for another time.
All in all, receiving on 6 frequencies on 3 bands, and with TX capability on 3 bands, is not too bad for two antennas.

I have yet to improve the RX/TX capabilities as described, but that is a story (or more stories) for later. For now I am happy with the current improvement.

You may ask, why this is of interest  . Well, I enjoy a local (or not so local) FM chat as much as many people, so there you have it.