Linear Amplifier for portable satellite station

[TMI]

...and decided to hook up a Power Plus HL-35V 35 watt 2 meter amplifier...

Don't suppose you have a source for this item? RF Parts currently lists a 2-meter-only amp: RF Parts Company

I am interested in this for use as a portable satellite station. I can hit AO-51 with my VX-8R just fine, and the downlink is clear. But SO-50 is much tougher for me to work, particularly as the UHF downlink seems very weak. Comparing the AO-51 downlink to the SO-50 downlink, the AO-51 signal is easy to find in the sky, and relatively easy to track/hold. SO-50, on the other hand, is like finding a needle in a haystack; it doesn't help that I'm often squirting the bird through evergreen trees.

 

[Moleculo]

That one on RF parts is very similar, except that it doesn't have the 2m preamp that mine has. Remember, it's a 2m preamp not 440Mhz. The bandpass filter on the amp won't pass 440mhz through anyway, so you won't be able to RX the 440 frequency on the satellite with it inline unless you split 2m/440 with a duplexer. If you're having trouble hearing the bird, try building this Ramsey 440Mhz preamp kit like I just finished here:

http://www.worldwidedx.com/home-brew-mods/35101-ramsey-pr40-440mhz-preamp-kit.html

BTW, which antenna are you using?

 

[TMI]

BTW, which antenna are you using?

The Arrow sat antenna (2m/70cm). HRO store had it with BNC connector, so I've added a short patch to convert BNC to SMA for my VX-8R...which also adds just enough length to make it all a little easier to use.

I'm getting S9 to/from our local 70cm repeater using that antenna, so I believe it's functioning normally.

...Tom

P.S.: Are you thinking of adding a couple of diodes to the Ramsey kit to reduce the voltage? I saw in another thread some discussion of this...

 

[Moleculo]

P.S.: Are you thinking of adding a couple of diodes to the Ramsey kit to reduce the voltage? I saw in another thread some discussion of this...

I'm going to try it as is for a while to see what happens. The worst thing that will happen is a 75 cent transistor will blow and I'll have to replace it, but I can't see that happening from only 2 volts over spec. If it does, I'll do something like the diodes which would be really easy. As the battery votage drops from usage it will be within specs anyway. Of course the gain will be less too, but thats OK. I don't think we have to worry too much about the transistor getting too hot either since a satellite pass is only about 10 minutes long.

BTW, the reason I asked about the antenna is that if you're going to use a small amp, you won't be able to use that built in duplexer on the Arrow antenna because it can't handle the power.

I got into SO-50 the first time I tried, but it was also at midnight. I haven't had an opportunity to try that once since then. I tried AO-27 yesterday and it was a zoo. There were a couple of stations that were obviously regulars since they knew each other. The seemed happy to tie up the satellite and not let others in trying to make any contacts. I heard another handheld station very well, but nobody could come back to him. Oh well, I guess that's probably par for the course on the weekend. A small amplifier would definately solve that problem