BATC Forum

Hi Gareth,

The best filtered pre-amp for 2 metres is this one from David G0MRF https://shop.amsat-uk.org/G0MRF_2m_Filt ... 28541.aspx

It was originally designed for an early SDR dongle that suffered badly from out of band overload.

detailed notes are here https://ukamsat.files.wordpress.com/201 ... _notes.pdf

It might not have the 55dB gain that Noel was talking about but it will be amplifying only the signals that you want!

good luck

Graham G3VZV

Looks interesting Graham

And I wasn't implying you need 55dB of gain but you do need something...

73
Noel

Thanks, one of the Amsat units ordered
On a related note, using other software for RX it crossed my mind that as SDRAngel does DVBS (video here https://www.youtube.com/watch?v=Bb8S_J9 ... Eu&index=2) and that my Pluto does 70MHz upwards I thought I'd give it a try.
Undoubtedly powerful but the GUI is very tricky for me, I could not get copy across the shack although the Pluto is clearly picking up something. I've had a quick download of Marks software but I can't select a device. So much to try, but good fun trying...

Gareth

I have used the g3sek 144MHz dg8 preamplifier in front of my tuner on 2m to successfully receive Noel and Mike. I also have a dg8 modified for 6m with 2 outputs and a dg8 modified for 4m with 2 outputs, both of which work well rejecting out of band signals
Dave
G4fre

Well success at last, out first 2-Way DATV contact on 2M, in fact our first DATV contact. I put up my portable 12 element ZL and tried adding a cavity filter then +18db of gain but MiniTiouner just couln't get a picture. Plugged into the Portsdown RTL with preamp and NO filter, +13dB signals at 125 SR. I could receive Martin at 250sr and occasionally at 333sr, he has a bit more erp than me.
Dongles not that bad at all after all.
Onward to boxing and switching and making things a bit safer!!

Thanks to the people who work to make this possible with hardware and software

Gareth

Hello Noel
The DG8 pre-amp is available as a short kit from SDR-Kits
https://www.sdr-kits.net/DG8-Pre-Amp-2M-Short-Kit

Any Mini-Circuits parts may require an EZ Samples application on their website to get them. FOC. It's been a while since I read the DG8 manual and I can't remember what's in it.

Regards
David M0YDH

All the other parts needed for the preamp are available from Farnell. The sdr-kits page refers you to the construction guide which in turn refers you to Ian's web site article at http://www.ifwtech.co.uk/g3sek/vhfdx/dg ... p-v7-4.pdf

Dave
G4fre