GB3VHF - Loud and Proud

Well,

I've been fiddling a little this morning with my 2M VHF setup; I have been using my TS-990 with a G4DDK transverter along with a DG8 masthead preamp.

It works extremely well; I use this set of "macros" to put the TS-990 into transverter mode and set things the way I like them:

$COMMAND OM0D;$ Mode USB-D
$COMMAND FA00028370000;$ 28MHz VFO Frequency
$COMMAND FB00028375000;$ 28MHz VFO Frequency
$COMMAND XO000116000000;$ offset 116MHz +ve
$COMMAND XV1;$ transvert on
$COMMAND AN00911;$ DRV on and RX ANT On
$COMMAND PA00;$ main preamp off
$COMMAND PA10;$ sub preamp off
$COMMAND EQT00;$ TX Equaliser off
$COMMAND EQR000;$ RX Equaliser off
$COMMAND BS01;$ Scope on
$COMMAND PC200;$ Power control to 10 (70W in non transvert mode)
$COMMAND BSC020;$ Scope Ref -10dB

And just for completeness:

Good egh?

Transverting - Complete!

Well,

The 4M Transverter I started back here:

http://g0mgx.blogspot.co.uk/2015/04/transverting-even-more.html

Is now **nearly** complete.I say nearly as I am still waiting for a ZLPLL board from here.

The interior has been completed and all wiring completed, here's a shot mid way though that process:

Now, you may remember that I have a Gemini 4M & 6M amplifier. Well, this was configured for a 25W drive level when I bought it, so I needed to modify it for the lower drive level of this transverter. The amplifier includes an attenuator which needed to be replaced. Here's a view of the Gemini with the covers removed:

In the photo above I have highlighted with a red circle the component that needed to be replaced. You can hopefully see that I have also had to remove the internal covers from the RF board screened enclosure to access the part.

Here's the RF board with the new attenuator installed:

This is working beautifully from the transverter now and giving me full power out from the transverter drive levels.

Good, egh?

Transverting - Even More More!

So,

Following from the start of the 4M Transverter project I posted about last time:

http://g0mgx.blogspot.co.uk/2015/04/transverting-even-more.html

I've done some more today.

The power amp module is built and mounted on the rear of the enclosure with an aluminium heat spreader:

The rest of the enclosure is prepared:

The internal wiring is almost complete, I've just run out of SMA cables - which is a bit of a bummer! I'm also waiting for the ZLPLL from here to complete the project properly.

Not a bad start though, egh?

How can something so Simple be so Tricky?

Well,

What a couple of days! I dropped the antennas down yesterday, the idea being to fit a Masthead preamp for the 2M antenna.

The preamp has been homebrewed, but I am sworn to secrecy as to it's design and origin. Needless to say, keeping an eye out here:

http://g4ddk.com/

May prove to be a most excellent idea if you happened to want one of these.

This is the basic board populated but still under test inside the house:

The board  gave me about 17.5dB of gain right across the 144-147 MHz range. This is a close up of the top of the amplification peak on the Spectrum analyser:

So I took the antennas down (which involves taking the closest element to the ground off the HF beam):

and I fitted the pre-amp. Now, this involved replacing the direct feeder to the beam and introducing a joint in the coax (so I can remove the amp if needed in the future).

So the preamp in in the waterproof box you see above, after many iterations I have the set-up working perfectly. I have, during the process, proved how completely incompetent I am at fitting N-Type connectors!  I've got there in the end though - only about a day and a half elapsed time!

All told though, a most excellent result.

Freddie has become exceptionally clingy to me since I returned from the Middle East earlier this week, hasn't helped much today though:

Local conditions.

Good, egh?