BATC Forum

Hi all after putting the Portsdown together what are people doing to get from the flea power to usable output ? I've used Robs M0DTS design for 2m using the RD06/RD15 and on 23cm I have a surplus 1800mhz PA that gives me around 10W, but what are others using ? has anyone come up with something cheap and easy for 70cm ? I see that the RD15 can be used upto around 500mhz at reduce gain has anyone tried it at 70cm ? I did buy one of the broadband 2w pa's off ebay but that proved to be a waste of time in its original state, although I haven't given up yet I've bypassed the first stage and reduced the bias on the final stage to 4.5v and it seems a lot better with well reduced output (need to get it checked on a analyser next).

Cheers John

70cm only needs a brick amplifier and filter.
You will need to attenuate the input from the Portsdown or it will give 50W out

I ordered a 60w 70cms amp from Roberto DG0VE.....Roberto reckons it will give out about 15w on DATV
http://www.dg0ve.de/en/poweramplifier%200,1-%201ghz.htm

Whilst the brick option is going to be an easy route its by no means a cheap one, what I'm after is just a few watts on 70cm so when portable don't have to think about too many amps and battery drain. I have got a 10W brick for 70cm but although that works with my handheld but just wont work with the portsdown. I have found my old MM 70cm ATV and that has a 20W PA which seems able to give a couple of watts from the portsdown but dont really want to remove it from a working bit of kit. There are some very cheap GSM bricks on ebay but I wonder how easy it would be to get them down on 70cm ? Eventually I'll go down the brick route for home, but got to get some antennas up first ! No antenna clause, but seeing as everyone has their sky dishes up no will start putting things up.


John

G7JTT wrote:Whilst the brick option is going to be an easy route its by no means a cheap one, what I'm after is just a few watts on 70cm so when portable don't have to think about too many amps and battery drain. I have got a 10W brick for 70cm but although that works with my handheld but just wont work with the portsdown. I have found my old MM 70cm ATV and that has a 20W PA which seems able to give a couple of watts from the portsdown but dont really want to remove it from a working bit of kit. There are some very cheap GSM bricks on ebay but I wonder how easy it would be to get them down on 70cm ? Eventually I'll go down the brick route for home, but got to get some antennas up first ! No antenna clause, but seeing as everyone has their sky dishes up no will start putting things up.


John

John
I have a ex pmr amp for 70cms which might suit your needs ....if you email me I will send you some pictures of it ....if you want its free essexsteve@icloud.com

Just wanted to say thanks to Steve G4HTZ for the donation of the amp and Dave G8GKQ for the help setting up the levels for a clean 4-5W on 437mhz. So I'm now QRV on 4 bands 2m,70cm,23cm & 3cm all QRP at the moment but that suits me. Thanks to everyone involved in the project and all the help received.

John G7JTT