[AMPS] Re: Your Aplha 374

[tkass]

tkass wrote:

> Hello Steve...well....when I got the Alpha 374  I noticed that one of the
> rubber air flow tubes over the 8874 was cracked and blistered...turned out
> that that tube showed a very high resistance short so I removed it.....while
> talking to a guy on the net I came across one of the Alpha (ETO)
> workers....he stated that the cracking was a common problem due to the poor
> cooling system..this was later changed on the alpha 76 ....he stated that
> once the tube super heated...it would crack the rubber...then a carbon trace
> would appear to eventually run down the side of the tube eventually causing a
> short to the base of the tube and causing tube failure....He recommended
> installing a higher volume blower...which I found one locally....I believe it
> has a name like Mitsubishi or similar...like the car...anyway...it is made in
> Japan and is all metal, no plastic, has more blades than the original....I
> think you can find these available in flea markets or surplus shops...got
> this one at Mindlesons Surplus in downtown Dayton, Ohio....$5.00....
>
> So, currently, am running only the two 8874....dont really need the 3rd
> one....as far as other mods....there was a factory mod to bypass the Grid
> Overcurrent LED as they were having problems using it was other HF
> radios...was kicking out the relays...particularly using the KWM-380.with the
> amp.
>
> As far as running the 3CX800A7....several people told me that it was a direct
> plug in...though can imagine they would set next to each other...not enough
> room...more likely on the first and third placement...anyway...then you had
> to add a separate filament transformer to get it up to the 12 volts
> necessary...I was wondering..since the 8874 run 6.3 volts, and if you were to
> run only one or two of the 3CX800....I would assume you could just place a
> voltage doubling circuit in the amp and forget about the extra
> transformer...looking at the filament current requirements...it is half that
> of the 8874's.....anyway...will likely keep the amp...had one guy respond but
> he found a 374A with 160 meters on it...dont know if he knows that that amp
> runs only 2 of the 8874's and I think the hypersil transformer was an option
> as well...let me know how your doing on yours...would be most interested in
> what you find out....73    Tim  WB8OWX.
>
> ab2et@juno.com wrote:
>
> > Tim,
> > In your "For Sale" message you indicated that you "replaced older blower
> > fan with higher output fan...some
> > factory mods"
> > I am in the "restore" phase of my 374 and just finished rebuilding the
> > control board when I noticed your message, do you remember the make and
> > model of the replacement "muffin" blower?
> > And any chance in knowing what the "factory mods" are all about, I picked
> > up a "parts" 374 but it did not have a blower any more, and my "prime" is
> > making some NOISE.
> > What is the source of the 3CX800A7 change out mod....
> > Any info that you can provide  will be greatly appreciated
> >
> > 73's
> > Steve
> > AB2ET
> > ________________________________________________________________
> > YOU'RE PAYING TOO MUCH FOR THE INTERNET!
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