Further to the 5.7GHz posting I bought, from the South Birmingham lads, a pair of transmit/receive boards for 5.7GHz. This was several years ago, I have done nothing with them as yet. The printed line filters on both boards say 5.4 – 4.9GHz, with extensive use of gasfets. The TX one uses an M76 DBM and the RX a single diode.
Anyone any experience of them ?
They look very useful, as soon as I can get a LO running I can at least give the RX one a try, GB3MHZ is only a few Km away.
I have some photo’s, if anyone wants a look see I can e-mail them to you, save bandwidth on here.
73’s Colin de G8LBS – suffering ‘man-flu’ from the Covid jab (OAZ) yesterday.
Sent from Mail for Windows 10
From: John Fell
Sent: 03 February 2021 11:45
Subject: Re: [UKMicrowaves] 6Cm?
There was an article in Radcom Microwave column a couple of years back showing how to modify a Franko Sat LNB board to produce a low noise front end for 5.7GHz .
I have one and it has around 1.5dB noise figure and 15dB gain , which would be a good start towards a TVTR.Followed by an ERA gaas Mod amp .
Evanescent filters are easy to make and will give you bandpass after the front end stage .
Build/buy a synth board to provide a lockable LO for TX/RX and bosh some i.f. passband filtering together .
Add a couple of mixer stages and some control system/sequencing and you are there .
The Birmingham lads (G8OHM) have/had PA modules at modest second hand prices for 8W output .
I would start with the RX and use the Beacons available locally to you (GB3OHM on .900 and GB3ZME on .910 +/-a few kHz ) .
Have added a 5.7GHz VE4MA to my 60cm 10GHz offset dish ,off boresight in the horizontal - seems to have little influence to the 10GHz LNB and just needs you to offset on your rotator readout .
Hope to use my Kune TVTR on EME next , after 24GHz tests .
It's just stopped raining !