A repeater, Really?

Well,

Whilst musing at the recent HamFest myself and my chum Vince, G0ORC decided it might be a good idea to learn something of the new System Fusion technology.

Having studied a repeater coverage map and concluding there was nothing near us, we decided that the best thing we could do was to put a repeater on the air.

This started the application process for GB3BP a 70cm System Fusion repeater.

We spoke to our friends at LAM Communications and they agreed to sponsor the repeater and provide the Yaesu DR-1XE we need.

So far we have frequency clearance for Input 438.4875 MHz and Output 430.8875 Mhz, and we are waiting for the NoV from Ofcom. We also need to purchase a Duplexer and it's looking like this is the one for the job:

http://www.mixw.co.uk/CAVITY/MDF1-6-70cm.htm

More to follow, but we should be up and running soon.

This page includes the calculated coverage map which looks very pessimistic to me:

UK Repeaters

and here is a page I have setup for the repeater itself:

http://www.gb3bp.uk/

Fun egh? Local conditions.

Its a funny old world

Well,

I have a good relationship with the chaps at LAM Communications in Barnsley. I received a parcel from them today which was addressed thus:

Which was fairly amusing....

I have also recently done a video for them on Digital Modes and the FT-991 which can be found here:

Good egh? Local conditions.

Baluns - Yet Again!

Well,

Part of the Windom I made last time here was a 4:1 balun. Now I tested one of those way back in time here. Back then I didn't much like what I saw as the frequency increased - it looked like the balun was only good to about 4MHz.

I came home with one of these the other day:

I bought in from LAM Communications in Barnsley.

Now, I repeated the tests I did way back when on this new balun and got more or less exactly what I expected. Here I am inputting a signal at 2MHz into the balun and looking at the two signals out. My expectation is that these two signals should be 180 degrees out of phase, as they are here:

The yellow and blue are the two outputs and the purple the difference between the two.

Now, as I increased frequency the last time I tested a balun this picture got very much "out of bonk" (a technical phrase meaning broken) with the phase difference between the signals moving significantly. On this balun all seems well at 25MHz and higher:

So - this balun seems to have good performance over the advertised range of frequencies - much better than the last one I tested!

As a consequence this is the balun installed on the new Windom.

Local conditions.