[ARC5] [cca] AN/APR-9B and AN/APA-70C question

[zakariya.abu at yandex.com]

Hello Mike,

Thank you very much indeed for the rapid reply and the well-structured 
AI article, which I find reliable.

I also think that the data on the AN/APR-9B and AN/APA-70C combination 
was correct as evidenced by the Grumman AF Guardian SAC documents, which 
can be downloaded from these websites:

https://www.aahs-online.org/images/Navy_SAC/AF-2W.pdf

or:

https://www.generalstaff.org/CDA/Air/AF/AF-2W_Guardian_SAC_1_OCT_1947.pdf

The 'W' variant of the AF Guardian was used for adversary target/radar 
detection using the radar of CM receiver with DF.

My only question is what was the 'interface' between the AN/APR-9B and 
AN/APA-70C as this matter remains unknown at the moment.

73,

Jan SP5XZG


W dniu 10.04.2026 o 20:31, Mike Peace - VK6ADA via groups.io pisze:
> Hi Jan,
> 
> Here's a post that contains some relevant answers to your questions:
> 
> https://vk6ada.com.au/the-an-apr-9b-and-an-apa-70c-on-the-af-2w- 
> guardian-passive-radar-homing-in-cold-war-asw/ <https://vk6ada.com.au/ 
> the-an-apr-9b-and-an-apa-70c-on-the-af-2w-guardian-passive-radar-homing- 
> in-cold-war-asw/>
> 
> 73s,
> 
> Mike
> 
> VK6ADA
> 
> On Fri, Apr 10, 2026 at 11:51 AM zakariya.abu via groups.io <http:// 
> groups.io> <zakariya.abu=yandex.com at groups.io 
> <mailto:yandex.com at groups.io>> wrote:
> 
>     Colleagues,
>     I am writing with a technical question, since I don't know any other
>     more knowledgeable people on such matters than you.
>     My question is related to the A.R.C./Collins/AIL AN/APR-9B
>     countermeasure receiver, which was apparently used with the AN/APA-70C
>     indicator. An image of a C-654/APR-9B Dzus tuning control can be
>     found here:
>     https://militaryantiquestoronto.com/product/ww2-us-early-warning-
>     radar-receiver-control-model-c-654-apr-9b/ <https://
>     militaryantiquestoronto.com/product/ww2-us-early-warning-radar-
>     receiver-control-model-c-654-apr-9b/>
>     Plenty of ID-304/APA-70C indicators can be found these days on the
>     web auction portals, eg. here:
>     https://www.ebay.com/itm/127342018932 <https://www.ebay.com/
>     itm/127342018932>
>     https://www.ebay.com/itm/175229218743 <https://www.ebay.com/
>     itm/175229218743>
>     These look almost like typical VOR/ILS navigation indicators of that
>     vintage. However, their nomenclature suggests that they saw more
>     specialized service.
>     The available online documentation listed the AN/APR-9B and
>     AN/APA-70C as used on the Grumman AF-2W Guardian ASW aircraft. Link
>     here
>     (see p. 457):
>     https://www.history.navy.mil/content/dam/nhhc/research/histories/
>     naval-aviation/dictionary-of-american-naval-aviation-squadrons-
>     volume-1/pdfs/app1-1.pdf <https://www.history.navy.mil/content/dam/
>     nhhc/research/histories/naval-aviation/dictionary-of-american-naval-
>     aviation-squadrons-volume-1/pdfs/app1-1.pdf>
> 
>     My question is: was the ID-304/APA-70C indeed used with he
>     AN/APR-9B, and if yes was it used as an aid to the crew to DF and home
>     on an adversary radar transmitter (eg. installed on a vessel) to
>     facilitate an attack?
>     73,
>     Jan SP5XZG