Batboard

Hey all,

I'm looking for some sort of specification on an AC to DC Power Supply for an Astro Spectra 110w radio that will be sitting at my desk. It needs to be able to handle me TXing on it.

What do you guys use? What should I be looking for as far as amps??

I'd be looking for a supply that can do at least 35 amps continuous. Astron RS 50M. 37 amps continuous. GARY N4KVE

What if I knocked the power down to just 50ws?

Astron makes some decent supplies for radio gear. Here is their catalog link - http://www.astroncorp.com/catalog.asp. I run a 100 watt Kenwood on 6m FM using an Astron SS-30 power supply. No brick down duty cycle, but it seems fine on 100w RTTY service for extended sessions. Current draw is about 22A. On a 65w Icom, the current draw is about 10A.

What's the current draw of the Astro Spectra radio in key down, and what is your duty cycle going to look like? Switching supplies have the advantage of lighter weight and less heat.

The RS-50M looks tough, but I think that it's a class A supply which means hot and heavy. If the current draw on your radio is 25A or less, you may get by with the SS-30. If you are looking more than 25A or at a high transmit duty cycle, the RS-50M is a better choice.

PL

You might also look at the Duracomm DPS switching power supplies.

I used an Astron RS-35 power supply to check out a 110 watt VHF Spectra on my bench with no trouble at all; it wasn't even breathing hard. The duty cycle for the tests was roughly equivalent to a normal conversational exchange and I am NOT claiming that it would handle continuous duty as in repeater service (but, then again, neither would the radio for that matter). That said, for use as a normal base/control station I believe that the RS-35 is more than adequate. I'm sure that there are those that will vehemently (violently?) disagree and insist that the MINIMUM rating would be somewhat higher but my response is that its always easier to spend someone else's money than your own. For what it's worth.
Tom DGN

I have a couple 110w radios installed in my truck on 30A fuses in a fuse block and none have ever blown a fuse. An RS-35 should do fine; it's rated to 35 amps at 50% duty cycle, 25 amps 100%.

Be careful bumping the power down. As you approach 50 watts the PA's in most 110w radios start getting cranky.

VHF 110 w TX is 27.5 amps
UHF 100 w TX is 31 amps Per the service manual.

So MP 6.7 IS correct the 35 amp power supply is the one to choose.

So MP 6.7 IS correct the 35 amp power supply is the one to choose.

Yeah! And so is WB6DGN, thank you very much!