RCA AR88 Series Cabinets

[David Dunlop]

Well, January out this way, will not be missed at all from a weather perspective, but on the last day of it's existence, it has provided the start of a brand new learning curve for me.

Up until this morning, I have been blissfully under the assumption only one cabinet design was ever made by RCA for it's AR88 series of receivers. The photos used in all the RCA AR88 Manual publications shows a cabinet with the solid upper back, a data plate in the middle of it, and a large slotted opening at the bottom to access connections (now which apparently came with a cover plate).

This morning, a chap in Lancashire posted an RCA AR88D on eBay and nothing unusual showed up with his photos until the rear view. As noted below, the upper section of the rear panel is filled with large slotted vents and the access opening at the bottom does not have the surrounding fittings for attaching a cover plate.

That jogged my memory of a photo a friend sent me last year of the Victoria Air Museum in British Columbia. They have recreated the Wireless Room for the old airport. It contains two AR88's. One is rack mounted (not sure what series) and the second is sitting on the lower right corner of the desk. The rear of it's cabinet can just be seen, and it is also a slotted version (no idea what series it is either).

So now the questions start flowing in my head. Are these vented cabinets prewar RCA production, war production, or post war items for the CR-91? Also, I suppose, do other variations exist?

David

[RobinBirch]

I've just run upstairs and looked. Mine is the same as the one you show a photo of. From memory, not being in a position to take mine out and look at the chassis, it was made in 1944. It has a vented back and holes on the same position as the ones the looked filled in the photo with holes in the chassis to match.

Robin

[HamishBoxer]

Think mine's slotted at the rear as well.

[David Dunlop]

Gentlemen.

Great to know that at least four of these vented AR88 cabinets have survived so far and, Robin, based on your information regarding your receiver, 1944 saw both versions of the cabinet in production.

I just finished reading an article in Electric Radio Magazine about the National RAO-2/NC-120 Receiver. Apparently in 1938, the US Navy deemed this National receiver as unacceptable for shipboard use in their Catalog of Naval Electronic Equipment because. "…radiation of its local oscillator is beyond the safe limits prescribed for security." This same concern was also noted in the updated Catalog Supplement 1, dated January 1948.

It is possible this concern over electronic radiation was of concern to more parties than just the US Navy and might explain the fully enclosed nature of the non-vented cabinet RCA designed for the table top version of the AR88 series receivers. Assuming the vented cabinets started in production in 1944, why did they? The change does not look like one that would have saved significant weight or steel, or have been faster to produce. I wonder, therefore, if military units in desert or tropical areas were experiencing overheating problems with the AR88's and the only solution RCA had was to vent the cabinets? By 1944 radiation being detected from the receiver by the enemy may no longer have been an issue. The Americans had control of the Pacific, the Battle of the Atlantic was over and the Allies were well on their way to air superiority everywhere. Would be nice to find some formal documentation about concerns in the field with the AR88's, and it is too bad the production records from RCA in Canada and the USA have gone undetected since the demise of RCA. Probably ended up in a Rubbish Tip somewhere.

David

[onewatt]

Morning all,
I've always been partial to AR88's and have over the years picked up 1 or 2. Whilst I've not noticed the difference in the rear panel, I do have a couple of units in aluminium cabinets. I'll post a couple of pics when I get a moment. I wonder if these were made for postwar surplus rack mounted Rx's. There certainly commercial cabinets and very well made but a lot lighter.
Chris

[Daventry 5XX]

I have a very early AR88, no.3081, which I believe to be pre 1944, this has the slotted vents at the rear.

Alan