New to me RCA AR80

[turretslug]

Originally Posted by Radio Wrangler

Are there many in Australia?

I'm certain that I recall a number of posts from Australian forum members over the years concerning their one or more AR88s, and I reckon that we can take it as read that Australia would have taken a big part in WW2 Pacific theatre signals intelligence and monitoring, and with a lot of US equipment. The Americans had a serious and sophisticated code-breaking operation against the Japanese, who nearly got to Northern Australia. Australia's kinda big, too, so maybe there's more space for WW2 stuff to be salted away- after all, a large US bomber that vanished over Australia in 1944 took 50 years to find!

[thoyer454]

I made some space on the bench and removed the front panel last night. I was surprised to find the the front panel was made from aluminum. I didn't think aluminum was very prevalent during this time period.

Comparing the text from the other AR80 pics on the web the text on mine is different and almost looks like transfer lettering, not silk screening.

The call letters in the upper left lead nowhere. Best I could find was a listing in the 1941 callbook. Googling the name and address turned up nothing of interest.

The dials are metal, black background with white lettering. The bandspread dial has two scales but the viewing window is fixed in position unlike the band window which will move according to the band in use. The two scales are each 0-200 but they are opposite each other. When one is at 0 the other is at 200.

There are 6 bands:
0.5 to 1.26
1.26 to 3.1
3.1 to 5.4
5.4 to 9.35
9.35 to 16.125
16.125 to 27.3

The dial lens was some sort of acrylic that obviously couldn't handle whatever environment the radio was stored in as it shrunk, discolored and cracked. Unfortunately it was in contact with the bandspread dial and left a few marks on it.

My thoughts so far are that this is an AR80 that may have had the front panel damaged and W3JCI made a new one. The paint on it is textured and if it is a homebrew panel, he did a nice job on it.

The S-meter is in good shape. Interesting that the wires for the light in the meter are terminated at the meter and wrapped in tape. There is no meter light. So the only dial / meter / panel illumination is from those "eyebrow" lights.

I have located a manual for this radio and should have it early next week.

That's where things stand now.

Tom
W3TA

[thoyer454]

A couple more pics

[turretslug]

No particular intention of band allocation to the bandspread scale then- that effectively means that the bandspread drive and its associated (I think) 9-gang capacitor amount to an all-frequencies slow-motion drive on the main tuning drive. A nice feature to have, but an expensive way to do it compared to an additional cog or two on the main drive! Plus, the bandspread scale mask is provided but unused. That goes to reinforce the impression that it's a low-run set based on the bones of the AR77. Remembering your previous thread on the AR80 where it was mentioned as to how the AR88 was apparently based on a UK specification, I wonder if the AR80 was a stop-gap that could be run off in a hurry, so to speak, for that or a similar requirement? Whilst not as comprehensive or thorough in detail as the AR88, it would still have been a highly-performing set- especially considering that some British users had apparently resorted to using the more highly-specified domestic sets for monitoring purposes at the outbreak of WW2.

The plastic window over the tuning scale of the Scott RCH here had deteriorated in similar fashion, going dark yellow, crumpled and shrunken as if it had been left on a hot-plate. I haven't tried applying a match to it to find out if it's nitrate though! The tuning scale windows on AR88s don't seem to suffer or deteriorate over time in the same way, though the tuning scales themselves darken.

Colin

[Radio Wrangler]

The photos of the panel make it look like the labelling is silk-screen printed. If so, then some tooling had to have been made.

However, early AR88s are easily spotted by their engraved front panels. A fair number were made before RCA switched to the less labour intensive silk screen process. So if that set has silk screening, it would indicate that RCA was expecting to make them in quantity.

The AR77 also used chicken-head knobs so your set matches there. The big difference mechanically is that you don't have the curved side corners to your front panel.

Could your set be a special AR77 for a customer demanding a set with a flat panel that would go into a standard 19" rack?

David

[ms660]

I had what some would say was a later AR88, it had an engraved front panel....All original too.

Lawrence.

[turretslug]

The AR88 here (SN 011514, so seemingly mid-production) has an engraved aluminium front panel with very crisp and precise edges and cutouts- not an amateur job. I think of it as "featherweight edition".

[thoyer454]

Located a manual for this radio. Appears to have been a "field" radio (hate to be the one lugging it around......)

Anyone able to decipher the contract number? US Gov't, Canadian....?

Tom
W3TA

[turretslug]

What was the situation as regards amateur radio in the wartime US Tom? I wonder if RCA felt that if it was to be suspended in the near future, then they would still like to make use of the investment in AR77 tools/jigs/components for a military-orientated receiver that was at least slightly less daunting than the AR88 to move around? There were various receivers that were pitched as "morale", some of which weren't far off full comms receiver capability with RF and multiple IF stages, BFO, extensive shielding etc. The Scott SLR series were described as such, but being as big and heavy as an AR88 (and possibly more expensive to make, but without the sophistication) were something of a white elephant IMHO. The AR80 actually looks to be a better candidate for this category. In hindsight, big contracts get awarded in the urgency of war that may have side-lined rivals that would actually have been better.

Colin

[thoyer454]

Originally Posted by turretslug

What was the situation as regards amateur radio in the wartime US Tom? I wonder if RCA felt that if it was to be suspended in the near future, then they would still like to make use of the investment in AR77 tools/jigs/components for a military-orientated receiver that was at least slightly less daunting than the AR88 to move around? There were various receivers that were pitched as "morale", some of which weren't far off full comms receiver capability with RF and multiple IF stages, BFO, extensive shielding etc. The Scott SLR series were described as such, but being as big and heavy as an AR88 (and possibly more expensive to make, but without the sophistication) were something of a white elephant IMHO. The AR80 actually looks to be a better candidate for this category. In hindsight, big contracts get awarded in the urgency of war that may have side-lined rivals that would actually have been better.

Colin

I can't answer that question as I'm a bit on the young side (56) and history is not my strongest subject............

It appears that it could very well be a transitional type radio to bridge the gap between the 77 and the 88 while providing some level of portability for field use.

It would be nice to be able to decode the contract number and maybe unearth the contract to see who issued it and for what purpose.

I did find a library that has RCA archives but due to the state of the world right now they are closed. When they reopen I'll contact them to see if they have anything on either the contract or the radio.

https://invention.si.edu/rca-corpora...bulk-1914-1968


Tom
W3TA

[CarbonMike]

I have looked in my old QSTs again and this may be a clue. The AR77 was regularly advertised by RCA to the ham fraternity but can't find any ad for the AR88, so it looks like war production took precedence.

[John KC0G]

Re. post #29, amateur radio continued in the USA until the attack on Pearl Harbor on 7th Dec 1941. You might find this article from the August 1995 issue of QST interesting:
http://www.rfcec.com/RFCEC/Section-3...20W8LUX%29.pdf

I wonder about the price difference between the AR-77 and AR-88. In the 4th ed. of "Shortwave Receivers past and present, 1942-2013", Fred Osterman gives the new price of the AR-77 as $139. He did not show a new price for the AR-88. Osterman does not mention the AR-80.

Re. post #28, now that Tom has a manual, I hope that he might be able to educate us as to the differences between the AR-77 and AR-80.

Thanks and 73

John KC0G

[thoyer454]

Originally Posted by John KC0G

Osterman does not mention the AR-80.

Re. post #28, now that Tom has a manual, I hope that he might be able to educate us as to the differences between the AR-77 and AR-80.

Thanks and 73

John KC0G

First place I went when I got the radio home was Ostermans book and found no listing. Thought that was unusual until I realized that very little info is out there on this radio.

I have printed out an enlarged schematic of both the 77 and the 80 and as time permits I'll be comparing the two line by line.

Tom
W3TA