Transverting - Even More!

Well,

Following the success of my 2M transverter project back here:

http://g0mgx.blogspot.co.uk/2014/10/transverting-some-more-some-more.html

which I showed off working here:

http://g0mgx.blogspot.co.uk/2015/03/ts-990-on-2m-144mhz-no-way.html

I decided that I would like to have a bash at making one of these transverters for 4M. Sam, G4DDK agreed to supply me with a kit of parts for a 4M variant of the Anglian. There are about 40 or so component changes. This meant that the board needed the SMD soldering to complete the unit - the 2M version required no SMD soldering!

So here is the project in it's infancy:

And here with quite a few more components in place:

and here with it complete and in the tin screening box:

I've run all the basic tests and both the RX converter and TX converter are working fine. There is a 42MHz local oscillator (70 - 42 = 28) - as with the 2M variant, I have ordered a ZLPLL board from here:

http://zl2bkc.com/projects/zlpll/

to provide an external frequency reference to stabilise the on board LO.

I've started the PA board to go with the unit; it should deliver about 7W output.

I've decided that to avoid any switching between transverters I will leave the 2M box interfaced to the TS-990 and use this 4M variant with the FT-DX5000. That has a transverter output which is -10dBm rather than the 0dBm I require. I may have to experiment a little with the levels but I should be able to drive the 4M Gemini amplifier perfectly with this combination.

Let's see.

Freddy cat has been doing a fine job of being almost completely in the way throughout.

Local conditions.

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?

Transverting some more, some more

Well,

Following my progress last time:

http://g0mgx.blogspot.co.uk/2014/10/transverting-some-more.html

I've kind of finished (ready for test) the Anglian transverter.

Here's the finished article:

Here's the main transverter module:

This is the external DDS LO which stabilises the in-board LO:

And this is my hideous looking changeover relay for the 144MHz socket.

There's an Omeron relay on the underside of the board, even so it looks pretty hideous to me!

These are the things I am not so sure about:

• The case is metal but plastic coated. Have I got a good ground connection to the front, back and main parts of the case - should I add some specific earth tags on each part of the case?
• The changeover relay - need I say more!

Fun though, egh?