[ARC5] ART-13 and BC-348...Now for some AN/ARC-21 Info

[Scott Johnson]

Looking at the ARC-21 with my radio archeologists goggles on, I can see that this radio was a design gone wild, but what really baffles me is why the AF didn’t just cut their losses and move on, rather than modify hundreds of ARC-21s and create another monster in the form of the ARC-65.  I worked on them for a year or so until we got the ARC-190.  You haven’t lived until you open up an RT and find that the oil-filled plate tuning cap has spilled its lunch throughout the whole RT.  Thank God for TCE.

 

Scott V. Johnson W7SVJ

5111 E. Sharon Dr.

Scottsdale, AZ 85254-3636

H (602) 953-5779

C (480) 550-2358

scottjohnson1 at cox.net <mailto:scottjohnson1 at cox.net> 

scott.johnson at ieee.org <mailto:scott.johnson at ieee.org> 

 

From: ARC5 [mailto:arc5-bounces at mailman.qth.net] On Behalf Of Mike Morrow
Sent: Monday, May 30, 2016 10:59 AM
To: arc5 at mailman.qth.net
Subject: Re: [ARC5] ART-13 and BC-348...Now for some AN/ARC-21 Info

 

Scott wrote:

> ... may not have even had a VHF set, most SAC aircraft of the cold war era did not.

But this B-36J did.  There is definitely a control for the AN/ARC-3, on the vertical section at the rear of the center pedestal.  I identified it earlier as "C-404A/A Control panel for the AN/ARC-3 VHF command set".

> there is another ARC-21 control in the pilots center console

C-455/ARC-21 Pilot's control panel for the AN/ARC-21 MF/HF CW/AM liaison set.  

It is directly below the C-403A/A Control panel for AN/ARN-6 ADF.

The RCA AN/ARC-21 was a very unfortunate choice for the USAF and the US taxpayers.

 

March 1948 - Contract awarded to RCA for first prototype deliveries by June 1950. But that did not happen until December 1951.  In spite of the delay, the USAF decided to issue production contracts before any sets were available for service testing.

December 1950 to June 1952 - First production contract AF-33(038)-18325.  $54,021,975 for 3,915 sets, or $13,800 per set (equivalent to $124,600 in 2016).

April1953 - Second production contract AF-33(600)-24390.  $38,297,638 for 1,843 sets, or $20,800 per set (equivalent to $187,800 in 2016).  Contract terminated in June 1954.

 

There was also an un-pressurized version of the AN/ARC-21 to be developed as the AN/ARC-40, but it was canceled.

 

>From the very beginning the AN/ARC-21 had massive in-service failure problems that resulted in MTBF in minutes rather than hours.  There was also very little training and maintenance support.  RCA civilian technicians had to be flown across the globe to service the set in the early days.  That's why the USAF purchased so many commercial Collins 18S-4 and 618S-1 sets to fill the roles for which the AN/ARC-21 had been intended.  Ultimately the RT-128/ARC-21 was re-worked to the RT-128A/ARC-21, which required an additional expenditure of more than $4,000 ($36,000 in 2016) per set that was already delivered.

 

In contrast, in 1947 the US Navy awarded a contract to Collins for a similar overly complex and heavy HF set called the AN/ARC-26.  The USN rejected it as impractical after $1,000,000 was spent for development.  Out of that came the well-known Collins AN/ARC-38 (similar to 618S-1, but with stabilized master oscillator and a few other improvements) which fulfilled the same role as the USAF AN/ARC-21 in a significantly lighter, less complex, much more reliable, much less expensive system...and no pressurization.  The AN/ARC-38 cost about $6,000 per set ($54,200 in 2016).  That's one-third what the AN/ARC-21 cost the taxpayers.

 

The USN did not use interim HF sets while awaiting the AN/ARC-38.  The USN continued use of the AN/ARC-25 (combo of AN/ART-13 and AN/ARR-15) until the AN/ARC-38 appeared in 1955.  However, the USN did buy some AN/ARC-59 sets, which were simply the Collins 18S-4A with a standard set of crystals and the RT-380/AR nomenclature.  These appear to have seen service mainly in non-combat logistics aircraft.  Mine is marked for Fleet Logistics Squadron VR-1, which is still in operation.

 

Mike / KK5F


>-----Original Message-----
>From: ARC5 [mailto:arc5-bounces at mailman.qth.net] On Behalf Of Mike Morrow
>Sent: Sunday, May 29, 2016 3:01 PM
>To: arc5 at mailman.qth.net <mailto:arc5 at mailman.qth.net> 
>Subject: Re: [ARC5] ART-13 and BC-348 In Their Natural Habitat
>
>Dave wrote:
>
>> Can you tell which VHF set was in use?
>> http://www.nmusafvirtualtour.com/media/062/B-36J%20Engineer.html
>
>On that center pedestal one sees:
>
>C-404A/A Control panel for the AN/ARC-3 VHF command set
>C-455/ARC-21 Pilot's control panel for the AN/ARC-21 MF/HF CW/AM liaison set
>C-403A/A Control panel for AN/ARN-6 ADF
>
>Back at the radio operator area there is:
>
>C-451/ARC-21 Main control panel for AN.ARC-21 (mentioned already by Scott)
>C-544/APX-6 Control panel and DESTRUCT switch for AN/APX-6 IFF
>
>The MF/HF backup set AN/ARC-8 is the T-412/ART-13B (without vernier scale on
>dial B). The only MF frequency shown on the tuning chart for the CDA-T is
>500 kHz. The receiver is an AN/ARR-11...the BC-348-R.
>
>There are no signs of the presence of an AN/ARR-36 auxiliary receiver for the 

>AN/ARC-21.  That would have required another C-451/ARC-21 as its control panel.

>
>Mike / KK5F

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20160530/a3edbd41/attachment-0001.html>