David Bowman

Electronics Engineer, Amsat member with three wonderful rescue Greyhounds.

[N0JY @n0jy]

We have metal! The GOLF-TEE spaceframe will be at @hamvention

The spaceframe and deployable solar panels are open access and supported by ARDC. Lots of meticulous engineering, procurement, and volunteer time make it real.
Come see it w/model avionics stack at @AMSAT Engineering!

[David Bowman @g0mrf]

Bought a small hotplate for SMD soldering. Not tried this before, but need to build this demo IQ modulator for image transfer at 18kbs QPSK for AMSAT-UK FUNcube+ mission.

[David Bowman @g0mrf]

Yes!!
New country on satellite.

[David Bowman @g0mrf]

@KE0PBR Hi Paul.
Thanks for the Sat list.
AO73 beacon frequency is incorrect. It is 145.935

[David Bowman @g0mrf]

Holiday break over, but had some fun.
Thanks GU6EFB, IU1OZH, F5RRS, PD1B ON6TM for the SSB QSOs on AO-73.
Put up a half wave for 160m + 49:1 transformer with G1YGY.
Contributed 4kg of cooked chicken towards the rescue greyhounds Christmas lunch at Wimbledon Greyhound Welfare
HNY

[David Bowman @g0mrf]

@GomSpaceGroup The GomSpace eps with 2 Li-ion cells on the AO-73 CubeSat is still working well after 12 years in Space. 😁👌

[David Bowman @g0mrf]

@MARK_G0NMY @AmsatUK Hi Mark.
No pass through. Receive only, unless you want to add some relays. Circuit and assembly info is available as a download from A-UK.

[David Bowman @g0mrf]

70cm pre-amplifier kits for mode V/U satellite reception are finally available to members via the @AmsatUK shop.
https://t.co/B5ilw21buW
Should have some here for direct sales in about a week.

[Badger01 @dave_g4dpz]

Happy 12th birthday @FUNcubeUK -1
Still going strong in transponder mode!
73
Dave, G4DPZ
Hon Sec, @AmsatUK

[David Bowman @g0mrf]

@W8LR_Jerry Took your advice Jerry.
First QSO using the new preamp W8LR on EN70/EN80 a few minutes ago. Range 3700km ele 9 deg.
No breakthrough thanks to that notch filter with 50W on 2m. Also worked PD4HDB and N1IPA. Tnx QSO.
5 ele on 2m, 9 ele on 70cm

[David Bowman @g0mrf]

Need a UHF preamp?
I've just received these boards from PCBWay.
Should be 16dB gain on 435 with a 2m notch filter on the input. N F. Less than 0.7dB with power via the coax.
Should have the first one assembled tomorrow.

[David Bowman @g0mrf]

@jpucheu Yes. The 70cms preamp will be available as a kit in about a month on the AMSAT-UK shop if you are a member, or from me if you are not. There are 3 x 0603 capacitors on the input. I'll solder those on the board as they're a bit on the small size for most people.

[David Bowman @g0mrf]

70cm Pre-amp update.
I have one assembled. Active device is a PGA103 from Mini-Circuits. The 2m notch works very nicely with -36dB at 145M. Gain on 435MHz is a fraction under +16dB. I need to look at the output low pass filter matching to make the response a little smoother.

[David Bowman @g0mrf]

@N4AKV_ @flo_0_ Yes. Will take about a month to get the parts. Then available via AMSAT UK for members or direct from me.

[David Bowman @g0mrf]

@N4AKV_ @flo_0_ Hi Jonathan.
After working Jerry, W8LR, on RS-44, I realsied I needed a masthead preamp. Sam G4DDK gave permission to use / modify his 'PGA432' 2016 design for A-UK.
https://t.co/tj3UkSOUKX
He does not produce kits these days, hence the PCBWay order. Looking good so far.

[David Bowman @g0mrf]

It's official !
Given a choice of RG213, Messi & Paoloni, or rotator cable. Squirrels, herons and foxes prefer to eat Messi & Paoloni ultraflex 7.
A QSO with FP5KE will be left for another day. :(

[David Bowman @g0mrf]

Arrived in Bochum for the FutureGEO workshop. On the way we managed to visit our old friends at Isispace and collect some flight hardware for our next satellite mission.

[David Bowman @g0mrf]

On my way to the ESA GEO satellite workshop in Bochum.
Hope this gets us a GEO that covers Europe and The USA

[Jean @ON5JV]

FP5KE - Arrived yesterday evening on ile aux marins. However, 11 pieces of luggage including all antennas and amplifiers were left behind in Canada. They do not know yet when the situation will be resolved and consequently when operations will be able to start.

[David Bowman @g0mrf]

Destined for the 6U Jovian-1 satellite, this mode U/V FM transponder had its first on-air test yesterday.
20W ERP on 70cm over a distance of 59km and a path loss of -150dB was received on a QFH antenna and retransmitted on 145.895MHz. Thanks to G0MJW and G3VZV for its first QSO.