Pace 23 ch series 2000

[Staybolt]

I've owned a few and every one of them had an odd hum. Yes I've replaced the caps, so why do tthese radios all have a weird hum?

 

[w9cll]

They don't know the words?

 

[nomadradio]

Maybe because it's a terrible design?

If that's the one I think it is, the audio power circuit has a single fat metal power transistor in single-ended class A. Throws stupid heat.

I was not fond of that design, and grateful the japanese knew better.

73

 

[Staybolt]

He'll if I know, I just know it has a loud hum. Kinda annoying. I don't know about designs ect as I'm not a tech, I'm just a chicken bander that likes to tinker.

 

[Trillo5]

I hope I'm not stating the obvious.....but have you checked your power supply that your using to power the radio? If its the Pace I'm thinking of , its a real basic mobile? I have had certain radios cause a hum and others don't on my bench power supply and found a bad filter cap. It was wasn't super off spec, but I replaced it and haven't heard the hum since. I think some radios seem to be more sensitive to RF noise than others. Also 1.1 choke might help as well.

 

[sunbulls]

Maybe because it's a terrible design?

If that's the one I think it is, the audio power circuit has a single fat metal power transistor in single-ended class A. Throws stupid heat.

I was not fond of that design, and grateful the japanese knew better.

73

Spot on! Be very careful if you decide to test for heat with your finger on that back transistor. I had a customer burn her finger while she was removing that Pace. We never sold those, but only had taken a few of them in for parts on a trade deal. I remember trying to modify one using the push pull audio design that the Jonson 123A’s incorporated. I still have respect for many of the early solid state radios, but those will always be near the top of my black list. In this case, having pretty chrome front that matches the style of many an early 70’s car is only eye candy.

 

[Staybolt]

A not even 15 yo Yaesu 30 amp power supply. Only radio that I have that hums.