Transverter News
Now QRV on 23cms
(1296Mhz).
I've now built a 23cms linear transverter based on Mark Kilmier VK5EME's
excellent kits, I now need to get on the air on microwave activity nights so the
regulars know to point their beams in my direction. The transverter is modular
with a 576Mhz local oscillator board, the actual transverter (transmit/receive
converter), a switching/control board and a power amplifier which gives around
14 watts output. I've built in the facility to control an external/mast head
preamp or linear as I don't think the 19 element beam I've got is really enough
but I think in my situation the broader beamwidth will be more beneficial.
50Mhz.
My 50 Mhz transverter, started a while ago but consigned
to the �pending� pile under the bench due to a failed transistor, now resurrected
with many thanks to G4HUP is complete at last. The design is Dave G4HUP's as featured in
the VHF UHF DX Book . Not totally built to Dave's
design my version uses a discrete PA section (2N6080 2N6082) instead of a
"brick", giving about 25 watts
.
During tune up of the receive side (22/10/2000) I was receiving a
GD0(zero) station at about S5 on a nice quiet band, so I did a comparison with my
�Porlock� based unit, the GD0 was totally obliterated by breakthrough of a
22Mhz IF image station at 10db over S9, this spurred me on to get the
transmit side going even sooner! All we now want is plenty of sporadic E and F2.
If you're wondering just how good the receive side is, I very rarely give a
worse report than I receive, even when running lower power. If you're into
construction I can recommend this totally, I have an FT-690Mk2 but this
transverter's performance is in another league. The transverter I was using is based on a
"Walford Electronics Porlock" with a discrete PA, I did think it
wasn't too bad but after getting the G4HUP working on RX I'm converted if you'll
forgive the pun! 70Mhz. Finished construction of a
transverter design also from the VHF UHF DX Book for 4m. Receive works well but
having problems with the TX side, PA stage was taking off, the PA transistor was
being silly! I just have to sort the bias out now, it gets raspy on speech peaks?
I haven't done anything with the bias circuit yet as I've got other projects on
the kitchen worktop! a 30pW to 100mW wideband power meter and a digital synthesized
6m SSB transceiver, I'll keep you posted.....