9cms TX RX on Ebay

[g8lce]

Anyone know about these?

https://www.ebay.co.uk/itm/252865647123 ... R-DU25mLYw

Martin G8LCE

[radiogareth]

Yes, The flat plate antenna are very easy to adapt to an SMA and have a gain of about 18dBi. I use a pair side by side RX/TX which saves a relay....I have run 40W through one on DATV and nothing went up in smoke. There is also quite a good TXCO with adjustment on the motherboard. Hard to extract from the casing, you basically have to cut all the edge-moulding off- I think they were thermally welded halves.
Gareth
PS, bought another pair so I can try 4 stacked......

[g8lce]

Could an array be used for 360 reception at a repeater? I guess the answer is yes. So if a repeater group bought some they could have one aerial for their TX and the other donated to their repeater for it's receiving aerial array.... (come on GB3NQ people)

Martin G8LCE

[radiogareth]

Yes, I think they could.....John G8MNY used multiple arrays of Bi-quads (Tri-Quads??) on the original GB3HV I think, to achieve good coverage.
I don't recall the beam-width of mine but its pretty broad, I think I was visible to Dave and Noel when out /P, they were separated by about 50 degrees, unless my memory fails me....
Gareth

[radiogareth]

Arrived today, just like the others I bought. RX and TX strips visible but TBH its easier to connect a Pluto/Lime these days, the stuff is TINY!!
Pictures show whats you get and the mounting problem in the old case.
The front cover, once separated, is about 2mm too shallow to allow re-sealing the flat plate, but you could use some rigid plastic sheet, and a non-acetic acid silicon to seal the whole lot back up and bridge the gap between the plastic sheet and front cover, a bit like sealing around a bath tub!. No mounting solution though...
Pictures should expand on this....
Gareth

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[g8lce]

Thanks Gareth,

Next will be the photos of your mods hopefully. Mine has also arrived so I will be getting the multitool out to cut into one! Then I will look at the electronics.....

Martin G8LCE

[radiogareth]

Probably the easiest conversion ever.....
Unscrew the PCB from the backplate, drill mounting holes for your SMA (2 holes enough), bolt on SMA, replace PCB panel and solder centre pin.
Depending on TX power you may wish to beef up the thinner traces that feed the assembly.
My nanoVNA shows VSWR at 1.7:1 at 3.4, a couple of dips further out, one each side of 3400, but that's fine, both my amps have circulators on their O/P.Gareth

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