[600MRG] Loudenboomer PA junk...

[Dave Riley]

Heathkit _SB600_  'rework' Dave Riley, AA1A


On 1/26/2018 11:59 AM, Edward R Cole wrote:
> Want a cheap high power amp?  Modify a stereo amp by removing audio 
> transformers and audio bypasses with 0.1 uF.  I'm told the power 
> transistors are able to run at 500-KHz.

Or throw your grapling hook in to the junk pile and 'Golly Gee' a simple 
old broken down Heathkit SB200 yet...

1. Buy/install a new face plate on ebay, DONE
2. Rework remove input switches and L/Cs to a single band ( 630m ) 
cathode input, tuned and DONE
3. Install aftermarket step start and external relay mods, DONE
4. Rework output band switching by removing most of it, DONE
5. Install 'external' plate tuning circuit, _keep DC to ZERO VOLTS 
outside of the case please_, or you are DONE

It was my WD2XSH/17 summer project in 08 and was needed to make 20W 
erp... It was more than adequate...
Hummm, maybe it needs to go on 2200m now...  Not done...

Anyway the filaments in this blunderbus are too expensive compared to a 
low volume air fan on to a pair of IRF460s built in to a surplus 
Mitsubishu A7DC chassis..
Idle signal state = NO CHARGE...

http://www.radiocom.net/600M/SB600M2.jpg
http://www.radiocom.net/600M/SB600M3.jpg

Regards from TinkerDave @ aa1a     Got Junk??



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