Nice Bargain at VHF Day.

 Yesterday, 11th January I went to the Winter VHF Day in the town of Ringsted.

As always great to meet other VHF-up people and exchange tall tales.

There is also a small flea matket, and I got two things home.

A programmable attenuator 0 - 120dB in 10 dB steps. specified up to 2 GHz. Another addition to the test equipment for the higher frequencies.

The second thing was a bit of a surprise. Someone had a Uniden scanner, the 3300 on the table, and when I asked the price he said DKK 20.- (about $3) so I took it home, thinking that if it's a brick, it doesn't matter.

I tried to switch on with the battery - of course it was dead. I found a suitable DC connector and connected 12V. Switch on, and the4 display showed something that looked like a functioning radio. Neat.

Now to find out how to program frequencies, so we can see if it really worked. Downloaded the manual and spent some time to get the right menu going. Finally I could enter a frequency. 

When I looked up the spec, the scanner should be able to run from 1240-1300MHz, so I entered 1297.500MHz, and restarted the radio, transmitting on that frequency. 

Bingo! Signal received. (Hearing audio feedback) The receiver works. 

I have not yet tested sensitivity, but even if it has poor sensitivity, I can use a preamp, and possibly a filter.

Now, a $3 radio that works on 1300MHz, that is what I call a bargain.

Temporary 28MHz Beacon.

 Fun little story from today.

I was, as usual, listening to the International Beacon Project (IBP) beacons on 28.200MHz.

Suddenly a big signal was coming in. I reralized that it was a test beacon from an Italian station.

S9 signal drowning the usual 18 beacons on the frequency. 

I found the email address on QRZ.com, and wrote a mail to him explaining the situation, quietly.

After a short while the signal diasppeared, and I got a reply mail telling that he was not aware of the IBP project, and he would find a suitable frequency.

All in the good ham spirit, and I do understand that we don't know every aspect of the activities, and we are usually, like here, willing to correct a mistake.

No, I am not going to reveal the call, because all went absolutely well. Mistakes happen, we have all made them.

CB Radios From Long Ago.

Yes, I have started doing a bit more radio again, let's see how long this lasts, as I need to de-clutter a lot.

Some time ago I got a box with a few CB radios, totally for free.

4 radios in different states, and all FM rigs.

First one (40 channels) tested worked in TX and RX. Power on and 3.5W TX output.

Second one (40 ch) had no TX output (nominal 4W) I had found that before, so not such a surprise

Third one (40ch) had about 2.8W out, and needed an external speaker to receive.

The last one was a 23 channel FM rig with 700mW out (nominal 500mW), b

I could probably find a replacement for the blown final transistor in #2.

All sets had, to my ear, poor sensitivity of about 2uV (-100dBm) for a well readable tone.

All worked on receive. #4 had poor audio., probably a defective electrolytic capacitor.

I think all those radios could use an alignment

Are any of those radios useful for anything ham related? In my view, yes.

- one or more could be used as a monitor receiver on 27MHz, for propagation monitoring (maybe a good use for the one with the blown final.)

- one could be modified and used for monitoring or transceive on 29MHz FM. I already have such a rig, so not so likely.

- I could use the casing of those radios, and build some home construction transceiver or receiver. The channel switch could be replaced with an optical encoder, and the squelch/volume pots for volume (duh!) and RIT control.

I have been thinking of some simple low power transceiver projects.

Anyone with other ideas?

23cm DX With the Vertical.

 This evening I had a bit of fun.

Listening on 23cm, well, I was simply having the IC9700 stand by on 1297.5 FM, and nothing.

Looking at the spectrum display (waterfall) I noticed a line around 1296.912. I had not heard any signals on that frequency before, so I checked, and out of the speaker I heard the DB0XY beacon in JO51EU. The signal was easily readable at the other end of the room, so actually quite strong at times.

I was a bit surprised, as this was with my vertical 23cm antenna, and most beacons work with horizontal antennas.

Distance 438km. Not bad with such a simple setup.

I need to get a horizontal antenna up again, and also getting a power amplifier up and running.

What a Mess. Projects.

 Yes, a literal mess.

The whole house has gradually become so messy that I have trouble finding space for a guest. Yes, that kind of mess.

So now the huge project is getting it pushed out. This may take some time, but in between there are a few radio related projects I want to get started, so I started making space in the electronics' lab.

While everything else in that small room is a total (well, not total, but still..., the workbench surface is now mainly visible, and I can access some test equipment and tools. It's still a long way to order, but slightly less chaos.

Now for some projects:

Antennas.

In freezing temperatures and snow outside? No, not for me. When the weather gets warmer and better again, there is still several antenna projects, as my antenna system has been deteriorating for a while.

I am glad I got my 23cm vertical up and running in a decent way, with a preamp at the antenna. It's working well in most directions, there are still some poor directions. 

A rotatable horizontal directional antenna is in the plan for better weather conditions. Some preparations are needed, so I will get there, probably in the spring.

23cm.

I can hear more stations than can hear me. I think this is due to my use of the preamp near the antenna, almost no one else around here does that with their verticals, just using an existing cable and possibly a triplexer. A quite lossy system to work with. So what do I do? Build a PA.

23cm Power Amplifier.

I got a linear amplifier built with 4 power modules. It is supposed to deliver about 50W, although I would not try that with a mode like FT8 (or other digital modes). I will need to build a coax relay system and more importantly, a sequencer, so I can avoid blowing up the preamp.

When that system is up and running, I will focus on another amplifier, running 40-50W, but for FM only.

I found a module in China, that has been used for sweeper jammers, a power amplifier covering 1200-1300MHz, with a nominal 50W output with about 10mW drive, quite some gain there. The module has no cooling, so some external cooling is mandatory.

This module requires a more elaborate sequencing procedure, as the output needs to be connected to a correct load before even applying supply voltage (28V). Initially all this will be indoors, but it could be mast mounted at a later stage. Ughh! Weather proofing needed, so maybe not ;)

QO-100 Uplink Power Amplifier.

My uplink system for the QO-100 satellite broke a while ago, the power amplifier blew at some experiments, so I need two things:

- repair the amplifier I had, if I can find the IC or transistor.

Before that I will be testing a 13cm PA module from SG Lab in Bulgaria.

This is my test setup. The mechanical part will come later.

This PA should deliver 15-20W (enough for the narrow band uplink) with a max drive of 40mW.

I intend to use my IC-905 directly on 2400MHz As this transceiver has a 2W output maximum, I will mount a 10dB attenuator, followed by a 6db attenuator at the inout of the PA, and then run the TRX at 80% output power. I don't want a power spike from the TRX to ruin the PA.

No relays are needed, as the PA has a built-in RF-VOX circuit with delay, not for the test. There is a PTT output from the IC-905, so that can be used in a permanent setup.

Surprise on 6m.

The solar activity has been low the past few days, and is slowly picking up again. 

Still, the past 2 days there have been a bit of DX spotted with my modest setup.

Stations from Vietnam, Indonesia spotted with FT8, and today I spotted VE1PZ in Nova Scotia. No, I didn't work any of them, but just receiving them is good.

With a solar flux as low as 163 that was a bit of a surprise for me.

I know. FT8 has made weaker signal detection much easier, we are in for interesting times.

New DXCC on 6m.

There have been DX signals on 6m every day for about 2 weeks.

I have received signals from 6 continents, and had QSOs with 4:

North America, Europe, Africa and Asia.

Last one was TR8CA today, Gabon, Africa using FT8.

All this with a small station, using a V-2000 antenna and 75W from my IC-7300.

I should try building a better antenna for 6m, capable of running more power. I do have a linear, and it would be nice to be able to run 3-400W with a bit of a directional antenna.