A Starter for 10GHz - RX Test

Well,

Myself and Vince, G0ORC headed to Alport today:

We aimed the antenna at the Leicester repeater GB3LEX on 10368.955MHz and here's what we heard:

It was rather foggy, but an excellent site that we will certainly visit again:

Whilst a very feeble distance:

This feels like one of my greatest achievements to date!

Local conditions.

Nearly Done - Starter for 10GHz

Well,

The final parts have fallen into place today. Firstly I have adjusted the HB100 from the ARRL $25 10GHz signal generator I mentioned last time to be as close to 10.368 GHz as possible using the LNB range extender for the Spectrum Analyser (also from last time).

The metal case contains a grub like screw underneath a QC sticker. Here you can see the device with the QC sticker removed. As luck would have it the trimmer for the coils in the transverters fits perfectly - you just turn the screw to adjust the frequency:

The other thing I have done is construct an interface box for the FT-817 to:

• Putting the 3cm transverter into TX by sending DC up the IF coax;
• Providing a AFSK digital mode interface from my laptop;
• Giving a CW keyboard capability.

Here's the schematic:

Please note that the 'DC up the coax' bits are entirely stolen from here: http://www.g3pho.org.uk/

The actual device looks like this:

and it interfaces to the FT-817 through the two rear sockets for ACC and PKT.

So all in all I think I now have a CW, SSB and digital mode capability on 10 GHz.

Local conditions.

More Testing - Starter for 10GHz

Well,

You may recall a while ago I started a microwave project called "A Starter for 10GHz" and I did some basic testing of the RX here. Today I have been to visit Peter, G3PHO and his amazing emporium of test gear; together we have tested the TX side of the project successfully.

I've done a few other things since I came back from visiting Peter - the first being to devise a way to get my DC to 1.5GHz spectrum analyser to display 10GHz signals following some excellent inspiration from Peter.

Here's a picture of a eBay purchased LNB:

This device is very high specification and uses a PLL local oscillator, here's the spec (in German) from the box:

So basically it's designed to receive 10.7 GHz to 12.75GHz with a local oscillator of 9.75GHz. If you inject a tone to the DC supply you switch to the 10.6 GHz local oscillator also available, but we don't want that for our purpose.

Now, I've made a very simple Bias-T to send some DC up the coax feed to the LNB:

and used this to connect the LNB to the input of my Spectrum Analyser:

 

Very much inspired by the ARRL $25 10GHz Signal Generator I purchased a couple of the HB 100 units from eBay for a few $s. I have added a voltage regulator plus a couple of caps:

This is switched on and running on the bench as is BTThing I told you about back here. BTThing is set to 2592 MHz making the 4th harmonic at 10.368 GHz.

The Spectrum Analyser screen looks like this:

The smaller peak to the right is BTThing. Doing the maths, we have:

Which is pretty damn close to the 4th harmonic calculation of 10.368 GHz.

Using a similar technique:

We can deduce that the HB100 $25 ARRL signal generator is on 10.345 GHz.

Local conditions. All good egh?