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Monday, 8 February 2016

23cm - From a hilltop?


I mentioned a while ago that myself and Vince, G0ORC were planning to have a bash in the UKAC contests. We have a capability for 6M, 2M and 70cm but nothing portable yet for 23cm. So hence the project....

I bought one of these transverters:

and to go with it a PA kit from G4BAO:

Here's what I've made so far:

I used a toroidal transformer I had to create the PSU, the requirements are 28V for the PA and 12V for the transverter.

The transverter module itself looks like this:

and the PA, once constructed, looks like this:

Now, the first conundrum was how to test the RX path of the transverter given that my signal generator only goes as high as 1GHz.

What I realised was that my Spectrum Analyser can be set into zero span mode and that makes the tracking generator a fixed frequency. So I set the Spec An to 1296.5 MHz and hooked it up like this:

With the F-817 set to 144.5 MHz I have a strong carrier - so I conclude that the RX chain is working.

Now to test the TX chain - more tricky!

First of all I realised that I can tune the input and output of the PA using the Return Loss Bridge combined with the Spectrum Analyser. Here's the finished result on the input side (after some trimming in accordance with the assembly instructions):

And here is the output side of the PA:

So now to devise a way to test the whole TX chain, this is what I came up with:

Which kind of looks like this:

So we have the RF from the PA into the big block which is a Return Loss Bridge, the -30dB port is feeding the Spectrum Analyser via another 25dB attenuator, then on the antenna side we have 2 x 30dB attenuators to a 50 ohm load. The return loss of this lot is actually quite good and looks like this:

Now, I have tested the transverter without the PA and can see an output at the expected frequency:

There's much less attenuation in the chain for the test above, but when I try and set the idle current on the PA it kind of runs away. By that I mean that as the device heats up so the current drawn increases and just keeps increasing. I think this is because I don't yet have any suitable heatsyncing in place so have ordered something which I will have to wait for before I can continue.

So far, so good though, egh?

Here's our latest addition currled up with her Dad:

Local conditions.

Wednesday, 3 February 2016

UKAC - Up there, Really?


We had our second bash at entering a UKAC contest last night. Myself and my chum Vince, G0ORC headed to the top of Alport Heights in Derbyshire with a generator, some poles an antenna, a radio and other bits and bobs.

Station seemed to work well and we headed home after 100 contacts due to the cold, damp and generally miserable conditions. The site is over 1000ft ASL and it was snowing up there last night!
Here's a map of our log:

Which isn't as good as what we achieved on 70cm a few weeks ago:

Now, the results are out for the 70cm test from January here: Results and it's clear we made quite a few errors in our operating and also logging. We are currently keeping a paper log and then transcribing it to electronic after the contest - there were some mistakes in the transcription too!

This is the result of the log analysis:

So all in all we have a 3/10 must do better!

Local conditions.

Tuesday, 2 February 2016

Well, Well, Well, what's news?

It's been quite a while since I updated my blog, and there's been quite a bit going on in my life. Primarilly I have been travelling to the Far East and back working for a living.

We've also had a new addition to the family, this is Bonnie Dog, she is the daughter of our Elmo and is a Sprocker Spaniel:

She is 12 weeks old today and quite a bit bigger now than the photo above, here she is with her Dad:

The shack is more than complete and already a total mess nearly all the time:

Myself and my chum Vince, G0OIRC have started dabbling in the Tuesday evening UKAC contests.

We bought ourselves a generator:

Plus a selection of antennas to cover 6M, 4M, 2M and 70cm:

We have been operating from Alport Top in Derbyshire IO93FB:

So far, due to my travelling, we have only done one 70cm test, but the results were very impressive. We are ready for tonights 2M test, so we will see what happens:

We are also planning to get a 23cm capability for portable operation, my current plan is to combine one of these transverters:

with one of the PAs from here:

Fun egh?

Local conditions.

Monday, 30 November 2015

Progress, Really?


I've concluded its tricky being DIY Dan whilst popping back and forth to Singapore. No matter how many times I travel, the distance and time zones do me in considerably!

The new shack is finally taking shape:

Some new bits n bobs too, new 'scope:

And also found this old Marconi Powermeter on my travels:

This was complete with waveguide to N-Type transition, attenuator and power head. A very nice addition to the test gear setup here. All I need to do now is learn how to use it!

Local conditions...

Tuesday, 17 November 2015

MB6GX - Experimental Wires-X Node


In my new shack I have set up a dedicated Wires-X internet gateway.

I hold two internet gateway NoVs; MB6GX for 2M and MB6IGX for 70cm. As the 70cm NoV stipulates that there is no unattended operation allowed (not even if I am in the house but asleep), I have opted for the 2M Node.

So, MB6GX is on-air and is an experimental Wires-X node in IO93GA on 144.8375 MHz; reports very welcome.

Fun egh?

Monday, 16 November 2015

Shack Move!


Do you ever take on a job and then regret it way before it's done? Here's my shack (old):

So it's basically destroyed!

Here's the new taking shape:

Cats already playing "shelf swat":

Local conditions. 

Saturday, 7 November 2015

Repeater Filter


You may remember last time I mentioned we were setting up a repeater.

I've come home from some work related travels to find the duplexer for the repeater at the house. It looks like this:

I've hooked it up to the spectrum analyser to see what the frequency response looks like, here's the result:

It's impressive, isn't it?