[Milsurplus] ARC-21/ARC-65

[Jim Whartenby]

Yes, the power supply data does not make sense at first glance.  Compare the ARC-65 data to the ARC-21 power supply data:


AFAIK, both dynamotor power supplies are the same except for the addition of the 400 cycle, 115vac needed by the ARC-65 side band modulator.  Both tables have the same DC ratings for the dynamotor power supply.  For the AC power supply, aircraft DC is still needed to run tube filaments and motors so there is an understandable difference.  Then there is the different power requirements between AM and SSBSC since there is no need for the high level AM modulator in the ARC-65.
Adding up both DC and AC powers (VA) for each operation in the PP-298/ARC-21 and compare it to the dynamotor we get:
                      Receive        Transmit CW               Transmit Voice           Tune
Dynamotor     687.5            1471.3                        1622.5                        1237.5AC supply      755               1405                           1497.5                        1305Not much of a difference.
Doing the same for the ARC-65:Dynamotor     722                1505.5                        1657                        1272AC supply     2450                2910                           2910                        4805Holy Cow!
Assuming that the AC current given for the ARC-65 data is 1/10 that shown in the table i.e. missing a decimal point:AC supply      690                736.5                            736.5                       975.5
Now with the lack of the AM modulator and the associated power it needs, the power requirements of the ARC-65 are perhaps more in line with what would be expected?
I don't have a PP-1831 but I assume it is a PP-298 modified to supply 115 vac 400 cycle primary power to the ARC-65 RT unit?I hope all of the formatting in the above tables gets through OK and doesn't add to the confusion!
BAMA has the ARC-21 manual and other interesting items for the curious.Jim I wonder why people argue over the 10% of their differences and ignore the 90% they agree on?

      From: Michael Hanz <aaf-radio-1 at aafradio.org>
 To: tbryan at nova.org; Milsurplus at mailman.qth.net 
Cc: Jim Whartenby <antqradio at sbcglobal.net>
 Sent: Wednesday, September 19, 2018 6:33 AM
 Subject: Re: [Milsurplus] ARC-21/ARC-65
   
 Hi Tom,
 
 From the manual:
 
 
            73,
  - Mike  KC4TOS
 
 On 9/18/2018 10:16 PM, Tom B wrote:
  
 
Hi Jim, I am also interested.  I have an ARC-65 that is on my post-retirement project list.  I have been collecting bits for a while now and I have most of what I need to get it going and a few spare modules.  
  I have the dynamotor, but one thing I would like to know is how much 400Hz power does it take?  Running from the dynamotor, I would not think it would need much AC power to run fans, etc.
  Tom Bryan
 N3AJA
 
 On 9/18/2018 1:20 PM, Jim Whartenby wrote:
  
 
 Bruce Gentry has expressed an interest in the above, are there any other list members who have any bits and pieces or whole assemblies?  I've sent Bruce a note off list of help to get his R-224/ARR-36 receiver going or at least add some of the missing modules.   
  Perhaps we can have an informal self help group to trade information and spitball any issues that come up?  It would certainly help motivate me to put more time into restoring this transceiver. Jim
   
 
  
 ______________________________________________________________
Milsurplus mailing list
Home: http://mailman.qth.net/mailman/listinfo/milsurplus
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Milsurplus at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html 
 -- 
Michael Hanz - KC4TOS ______________________________________________________________
Milsurplus mailing list
Home: http://mailman.qth.net/mailman/listinfo/milsurplus
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Milsurplus at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

   
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/milsurplus/attachments/20180919/95693a19/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: ARC-65 power requirements.png
Type: image/png
Size: 26525 bytes
Desc: not available
URL: <http://mailman.qth.net/pipermail/milsurplus/attachments/20180919/95693a19/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 51279 bytes
Desc: not available
URL: <http://mailman.qth.net/pipermail/milsurplus/attachments/20180919/95693a19/attachment-0003.png>