Power supply

[kb2vxa]

NOPE! It draws 20A so a 20A supply gives you ZERO headroom. OK, so don't listen to sound advice but don't come crying to me when you have problems with it; all I'll tell you then is I told you so.

 

[ke5ldo]

Astron 30A and above for base; Gamma Research HP1-A for non-mobile portable use. Both Will run 706 forever..

 

[prcguy]

Again, it depends on his use. Most people never use FM and for SSB the max average current for a 100w radio is about 10A. My TenTec Omni VII will run 100w in FM mode and TenTec recommended an Astron SS-18. Appearently the Astrons are a little underated.
prcguy

NOPE! It draws 20A so a 20A supply gives you ZERO headroom. OK, so don't listen to sound advice but don't come crying to me when you have problems with it; all I'll tell you then is I told you so.

 

[ratboy]

I would always go to the next size higher in a PS, as I have personally killed a couple of 20 amp supplies over the years, one of them about 4 hours after I got it. The bands were open to Western Europe and I was talking to all kinds of people from the UK to Spain, running about 95W and I had to go someplace and when I came back and turned the PS on, it popped the fuze and it was totally fried. The replacement one died about 3 months later, right after the warranty ran out, so when I bought the next one, it was a "35 AMP" supply, and it's been here about 20 years now.

 

[kb2vxa]

Well PRC not to be too pedantic one must remember dynamic regulation when dealing with CW and SSB peak currents. Without sufficient headroom you're plagued by flagging voltage on current peaks which can result in distortion, a not so clean CW waveform and "flat topping" of the SSB signal. It may be a 20% duty cycle which will not cause overheating but the supply will still be overloaded.

Hey Rat Boy, do you think my Tripp Lite PR-60 is up to the job? (;->)

 

[datainmotion]

Hey Rat Boy, do you think my Tripp Lite PR-60 is up to the job? (;->)

Warren - I trust you like the PR-60? I have one listed FS...

 

[prcguy]

All your points are valid and most hams I know have burned up an Astron RS-20 linear supply at some point and these supplies can severely damage your radio if the pass transistors fail in the short mode.

I'm recommending an Astron switching supply which does have limits but works a little different and would not damage your radio if it failed. I have owned an SS-30M, SS-26 and SS-18 for many years but my SS-18 in particular has been plugged in and turned on 24/7 (except for travel) for about 5 years and I have thrashed this supply with 150W Harris HF rigs and countless other 100W rigs at full power FM and it doesn't seem to care. The voltage doesn't sag or droop, it doesn't seem to overheat and its very small for travel. Why would a US radio mfr recommend this supply for their 100W rig, especially if they have to repair their radio under warranty if the supply damages the radio?
prcguy

Well PRC not to be too pedantic one must remember dynamic regulation when dealing with CW and SSB peak currents. Without sufficient headroom you're plagued by flagging voltage on current peaks which can result in distortion, a not so clean CW waveform and "flat topping" of the SSB signal. It may be a 20% duty cycle which will not cause overheating but the supply will still be overloaded.

Hey Rat Boy, do you think my Tripp Lite PR-60 is up to the job? (;->)

 

[Tryton]

NOPE! It draws 20A so a 20A supply gives you ZERO headroom. OK, so don't listen to sound advice but don't come crying to me when you have problems with it; all I'll tell you then is I told you so.

I bought a 30A PS not a 20..

 

[k5phw]

I was waiting for the others to catch that. :lol: