Re: [amsat-bb] How to connect DC to ARR preamp or dc injector?

[Lee Scott - AA1YN <aa1yn@xxxxxxxxx>]

At 05:50 PM 1/6/2005 -0500, Ka8syx2003@aol.com wrote:
>Hi, can anyone tell me how they've successfully applied DC to their 
>AdvRecResearch preamp?  The wife gave me an ARR 70cm GaAsFET preamp for 
>Christmas, along with a dc injector to send the juice up the pipe from the 
>shack.  All I can see is a stub coming out one side of each little box, 
>and a couple of nuts clenching a solder lug on the other.  Consulting the 
>schematics for the preamp, I see that the Vdc-in stub is actually one lead 
>of a feed-through capacitor.  What is common practice for hooking up power 
>to it?  I'm thinking about soldering the two wires from a red/black power 
>lead to each appropriate terminal on either the injector or the preamp and 
>terminating the power lead with a jack into which I can insert banana 
>plugs with (+) and gnd.  Would this be appropriate?  Opinions on the 
>neatest method out there?  Thanks, everyone!
>73, Ray KA8SYX
>Big Pine Key, FL
>EL94hr

Ray, if you have a transverter near where you are placing the pre-amp, you 
can modify your transverter by tapping off of the Rx power on the board and 
using that as a source of power for the pre-amp.  If the ARR pre-amp has a 
built-in bias-tee, you can add a bias-tee at your transverter T/R 
input/output (or rcvr input if seperate) and feed the Rx power up your 
coax. By your note, it sort of suggests it does have a bias-tee (DC 
Injector) since it came with an external one. Bias-tees are reliable and 
present no problems.  I use them here in the shack to sent xmit key signals 
to the transverters on the tower. If your system is a receive only, then by 
all means - use the bias-tee as it will be the simplest approach.

Of course, all other precautions pertaining to pre-amps apply.


Lee Scott - AA1YN http://www.aa1yn.com
Home of the VHF & Up Register http://www.aa1yn.com/vhf
Hooksett, NH
FN43gc52
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