[ARC5] AN/ARC-5 or ATA

[WA5CAB at cs.com]

I'm sorry but it's the SCR-274-N transmitters that are essentially the same 
as the ATA ones.  The circuit differences between AN/ARC-5 transmitters and 
the other two are significant.  The two major differences are that the 
connector on the rear of the chassis is different (so that you cannot 
accidentally plug an ARC-5 transmitter into the racks for either of the other two 
models.    And the final amplifiers in the other two have series fed B+ to the 
plates whereas shunt feed is used in the AN/ARC-5 (see the RF choke in the 
third photo which is a better identifier than the nameplate on the cover as 
covers are interchangable).  

System differences are that the ARC-5 transmitters are plate and screen 
modulated whereas the other two are screen modulated.  However, with due 
attention to the pin number differences between the two groups, it is possible to 
run an ATA or SCR-274-N transmitter off of an MD-7 modulator.

In a message dated 01/05/2012 20:43:25 PM Central Standard Time, 
dennis.monticelli at gmail.com writes: 
> Yes, that is an ARC-5.  Says so on the blue lable.  I have the exact
> same T-22 model.  The circuit differences between the ATA and ARC-5
> transmitters is minmal.  The info on getting the unit on the air is
> applicable to both types.
> 
> Your rig looks to be original and unmodified.  You can get it on the
> air successfully with minimal (and reversible) modifications.  Do not
> blindly follow the conversion articles of yesteryear.  Most of these
> mods are invasive and excessive.  Instead, look up a more recent
> write-up done by Dave Stinson, AB5S, in the ARC-5 archives.  Dave
> follows this reflector so perhaps he will be kind enough to re-publish
> his notes should you be unable to find it.
> 
> This reflector is also a good source of advice on cosmetic restoration
> and missing parts (such as the screws your unit is missing).
> 
> I hope you enjoy restoring and operating your T-22 as much as I have.
> 
> Dennis AE6C
> 
> On 1/5/12, Mark K3MSB <mark.k3msb at gmail.com> wrote:
> >I'm working on getting my first ARC-5 on the air.   There is a LOT of 
> info
> >on the web, and I'll admit to being confused as to the identity of what I
> >have.
> >
> >I think it is an AN/ARC-5 and not an ATA.  Is this correct?
> >
> >http://s1230.photobucket.com/albums/ee494/yeoldejunkman/ARC5
> >
> >73 Mark K3MSB
> 

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