Re: Last call for group buy of F6BVA QO-100 system PCBs etc

Colin Ranson



Just a quick throw into the air.  I currently run a lashed up  up-converter from 432MHz to 2400MHz using a SKY-60LH mixer and an ADF4351A LO at 1968MHz – it drifts as it has a crap 25MHz reference crystal.  Some amplification up to 500mW to drive a 20w SG-Lab amp. It needs a lot of improvement. (stable reference <the RX LNB one> and sharp LO filter) Prime mover is an IC-706MK2g – I did use an SG-Lab transverter but a hell of a waste and a pain.


RX is down converter from LNB IF 739MHz  to 144MHz (FT480) – steady as Gibraltar. I have been having thoughts about changing the LO in this to 307MHz to give /RX IF of 432MHz to give full simplex on a non satelite equipped radio – ie the 706.


Anyone done anything similar ?


Regards to all,   Colin de G8LBS.


Sent from Mail for Windows 10


From: Neil Smith G4DBN
Sent: 14 March 2021 13:54
Subject: [UKMicrowaves] Last call for group buy of F6BVA QO-100 system PCBs etc


As previously mentioned, I'm doing a group buy of PCB sets for the F6BVA
QO-100 up/down converter and MW7ic2725 PA.

This version of Michel's design is about making a simple standalone unit
for use over QO-100 without needing a computer or SDR dongle, and
without tying up the TX side of a 13cm transverter. Ideal for a go-box
with a 2m/70cm SSB rig and POTY-equipped dish.

There is already enough interest to do a group purchase of the
components. I will be providing some English-language construction
notes. The set of two PCBs is likely to cost around £40, perhaps a
little less if demand is high enough. Not sure of component cost yet,
but the Minicircuits mixer at £13 and MW7ic2725 at £50-ish are the only
expensive bits.

You'll need a local osc with two selectable frequencies. An SV1AFN or
even a Chinese ADF4350/51 would be good enough for QO-100 usage.

Sorry there isn't a converter-only option as the economics of fancy SHF
laminates and finishes mean we have to buy both boards, but you may be
able to find a home for the PA PCB if you don't need it.

For clarity, the older version was full-duplex, but this V3 is designed
to work with a simple half-duplex transceiver.  On 2m, you can use a
DF9NP LO using one of the control pins, but for the other bands (and
also 2m) you can use an SV1AFN or Chinese ADF4351 with a tx/rx
changeover flipping the frequency via a pin on the controller. I'll be
using an SV1AFN board. Not decided about the controller yet, might just
use an 8-pin PIC and PSU and TCXO on board, but that would just be
reinventing the SV1AFN controller. We'll be supporting this through the
IO group at which
you are welcome to join.

If you are interested, have a look at the document (in French) at

If you'd like to join a group purchase of the PCBs, with optional tin
box, milled aluminium PA box and full or part component set, please
email me direct to neil@... with title QO100 so I don't miss the

I'll be finalising the order to send to Pierre-François in the next day
or two, but the ultimate cut-off will be when he submits the order to
the pcb fab. I don't expect there will be a second tranche.

Neil G4DBN


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