Mobile to Base Power Supply Question

[TK-950]

Hello all, new to the forum, but so far I've found a lot of great info on here. I've brought my mobile CB inside to run as a base station, right now I have a Uniden Pro 520xl that I took out of my Jeep that has been peaked and tuned. I setup a A-99 antenna outside and was able to get the base of it a few feet above my roof ridge. I live in FL so I seem to be getting out pretty good with this setup so far. I am having my General Lee worked on right now and will be using that as my base when it gets back to me.

Right now I am using one of the small computer server power supplies to power my radio. It's rated at 85 amps, but only puts out 12.4 volts. It works great so far, no noise or anything like that. My question is, should I be looking for a more suitable power supply like a Astron or something similar that will put out a more appropriate 13.8 volts?

Thanks!

 

[Shadetree Mechanic]

Welcome to WWDX! The power supply you are using will probably be ok. I don't think raising the voltage to 13.8 would make a noticeable difference. I have a Uniden 510 in my work truck. They are nice little radios.

 

[tba02]

The only thing you would notice if you switched things up would be the dent in the wallet.

 

[TK-950]

Thanks, I wasn't sure, only because I've read in some other places that the lower voltage might effect the output of the radio somewhat. (maybe B.S.?) But I figured it was no different than hooking up to a 12v battery.

 

[Shadetree Mechanic]

The difference in voltage might mean a slight difference in power. The person on the other end will never know the difference. If you were running a big amp it might make a difference of 10 or 20 watts. Again nobody on the other end would be able to tell. There is a formula that equates power to S units on the recieve. I forget exactly how it goes. Maybe someone will chime in with this information.

 

[tba02]

It could potentially reduce output slightly but not enough to make a difference (as STM mentioned)

Assuming your radio, on AM, has a dead Key of 4 watts and peaks at 16 with 13.8 volts, your current setup would (in theory) produce 3.65 / 14.62 watts.

Depending on the specific power supply I have been able to bump them up to ~13 volts with a quick potentiometer adjustment and no soldering.

Spend the money on quality coax or other antenna related items.

1 S-unit = 6dB. You would need increase your output by factor of 4 for the receiving station to see an additional S-unit. That would be 64 watts needed to make the needle move a spot based on the assumptions.

 

[sunbulls]

Monitor the voltage when you key down under load. If it doesn’t drop below 11 volts, you’re good. Some equipment can become very unstable if the voltage drops that low. I doubt you will experience much fluctuation. Usually they will exhibit a stable voltage if you're drawing less than their current limitation. Old ones with leaky capacitors or other out of tolerance components being the exception.

 

[TK-950]

I checked mine last night with a multi meter, no drop at all when keying the mic. That's with the Uniden. I should have my General Lee from Bob's today and I'll check under load again once I get that hooked up.