[ARC5] Suggestions Needed

[joelroberts001 at comcast.net]

Hi Bob, Thanks for that info. The three spares I have, have the second tap on the secondary. I just need to get my VTVM out and warmed up so I can do some work on the others, and I'll test all for an open circuit. Then I will replace the one neon bulb with the broken lead. 73's,,,,Joel KB0FPT 

----- Original Message -----

From: "WA5CAB--- via ARC5" <arc5 at mailman.qth.net> 
To: joelroberts001 at comcast.net, arc5 at mailman.qth.net 
Sent: Friday, February 19, 2016 10:24:38 PM 
Subject: Re: [ARC5] Suggestions Needed 

Joel, 

There must be about a bzillion scrapped or butchered BC-453-B's and R-23/23A's lying around. There were only three audio output transformers made by A.R.C.for the Command Sets.ARA and AN/ARC-5 receivers used one, A.R.C. # 5631, which had a nominal secondary impedance of 500 ohms. The second (A.R.C. 6308) and third (WECo ES-691027) were used in the -A series and -B series of SCR-274-N receivers. The one used in the -B series (4000 ohm secondary tapped at 250 ohms) will replace the one in the -A series (4000 ohm secondary) as it is the same transformer with a secondary tap added. 

I realize that the secondary turns given in the various manuals don't seem to agree with the given impedances but that's what the Navy and Signal Corps claimed them to be. All of the transformers have the same primary (4000 turns of #40 AWG). 

As many of these things as there are around, there is really no need nor excuse for using something from RadSahck or Mouser as a substitute. It is highly unlikely that they have a reasonable substitute for the ones in the SCR-274-N's anyway. These latter each have nominal 4000 ohm secondaries, with the second one tapped at 250 ohms. 

Robert Downs - Houston 
wa5cab dot com (Web Store) 
MVPA 9480 

In a message dated 02/19/2016 18:11:57 PM Central Standard Time, joelroberts001 at comcast.net writes: 


Good evening guys, I need some help on finding substitutions. Ken suggested asking the group. I need replacements for the Neon Voltage Limiters for the AF Transformer, and also need subs for the transformers, not necessarily NOS. No Rad Shacks left so will need to hunt Mouser or All Electronics. Whatever help you can give would be great.... Joel KB0FPT 






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