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Boomer RX 75----Anybody ever seen one?

Hi ALL,
I just won this oldie on ebay. I don't have it yet, it was shipped on Monday the 29th from Nebraska and decided to spend the weekend in Denver Colorado. :D

So these are the only pics I have of it. and here's the guys description;
"Vintage Boomer RX-75. I had this back in the 70s, so it hasn't worked for 40 years. Never took it apart to check out what is wrong, I assume it would be fixable."

boomer1.JPG

boomer2.JPG

boomer3.JPG

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I know these pics are of no help right now, but was hoping someone may have had or have one?

I will post more photos when I receive it.
I took a chance, could be a loose wire:), or----------------blown outputs:(-----wish me luck.
Thanks
 

Looks to be a clone of the Palomar amps of the era. Probably has MRF-455s in it.

Good luck with it. If nothing else you can use it as a learning platform.
 
Looks to be a clone of the Palomar amps of the era. Probably has MRF-455s in it.

Good luck with it. If nothing else you can use it as a learning platform.

Thanks for the comeback Atlasta.
Palomar clone is what I was thinking, not by experience-----just interweb snooping. lol
You have the "learning platform" spot on. Regular AC-DC circuits I'm pretty--okay at. :) But RF-------I need the white stick and a dog.
The thing I found interesting about this guy is the RX gain pot on the right side.
Could find only one other pic of this amp, and it was just a front shot (face).
Hope I can get it to work. I had a little 50watter back in the mid '70s, and it did just what I needed---get over the noise level, not skip or stomp. Nice local jawjackin'.

It left Denver and will most likely be in Mi. Saturday and won't be delivered 'till Mon.

I'm like a little kid waitin' on Santa------------and I'm 59yrs old:LOL:
 
Well I just got it today (the 6th)
It has BLW60C pills, a 2n5136 mosfet for the receive amp, and two huge 1n3401 diodes.
I can't find a schematic even close on cbtricks.

The bad news------------it's a paperweight
icon_e_sad.gif

The receive amp no go, turn it on and rx goes in the crapper. Off it's good.
The xmit firing circuit is good, pulls in the relay, but zero on output. (relay contacts are okay)
Xmit and Rx is fine with it turned off.
My guess is, overdriven. But that wouldn't mess with the receive,
So power was probably hooked up bass ackwards.
New pills are $95.00----not gonna happen.

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Just my luck--------if it wasn't bad I wouldn't have any lol
 
You could re-bias it and run MRF455 or MRF454 if you know how to drill and tap.
I had a base amp that was blown and had the same transistors in it. I just modified it to run 454's and it actually put out more power.
 
The European market has a lot of transistors that will replace many of the now obsolete and hard to find devices that were commonly used here in the states some years ago. And many won't break your bank either. There are numerous devices but you have to get the original data sheet on the one you want to replace and then browse through many data sheets until you find one that will match. If you use their common cross reference then you will find a replacement a lot quicker but you will end up paying premium prices for them through places like MSI, ASI and others. ASI is here in the states but they buy and sell in bulk from the Euro and Asian market at a substantially high mark up. I've found several replacement parts from the Euro market and found them to be of high quality and durability for use in Marine HF and VHF repairs. I've also done a few repairs to Amateur HF and even some CB radio and amplifiers. I do stay away from the Asian components, I've had not so good luck with many of those devices unless they were original Toshiba parts.
 
Thanks for the replies guys.
I'm on a fixed income, so taking a chance that it might work isn't in the cards. :(

I'll throw this back on ebay--not working parts only.
Heck relays are good, heatsink, big diodes,transformers----maybe I should just part it out. lol

I'll probably save up and get one of those RM Italy 203 guys----about 83 bucks.
IDK

Chuck
 
You could re-bias it and run MRF455 or MRF454 if you know how to drill and tap.
I had a base amp that was blown and had the same transistors in it. I just modified it to run 454's and it actually put out more power.

Thanks Tallman,
I forgot to respond to your drill and tap question.
Yes I have a small machine shop setup in the garage, so drill and tap, no problem. lol
The circuit board on this is two sided. so I'm not sure if there's room to hog out the board for the surface mount flange. If not I could "blind nut" the flange, and run mounting screws from the outside.

Now who's got some doners for the experimental project-------:LOL::LOL::LOL:

Thanks again(y)
Chuck
 

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