AN/URC-8 HF Receiver & Transmitter

AN/URC-8(XN-1) Transmitter-Receiver - download Sales Brochure [PDF File]
T-474/URC-8 - schematic
R-627/URC-8 - schematic part 1, part 2
PP-1190/URC-8 - schematic

t474-urc8-01.JPG (37765 bytes) r627-urc8-01.JPG (32096 bytes) pp1190-urc8-01.JPG (28788 bytes)

I know nothing about this additional prototype:
AN/URC-8 (XN-2) Trans-Receiver Radio Set.

Info from John K4OZY:
First, a thousand thanks to Ken Bodensteiner @ Rockwell/Collins who came up with some advertising brochures for the URC-8. Turns out it was intended as a replacement for the TCS! You can view the brochures by clicking here: URC8 Brochure [PDF File]

URC-8 consists of
Mil Name Collins Part # Description
R-627 522-9273-004 Receiver, 2-30 Mc, 4 bands, AM/CW only, 2 mech filters, 107 lbs
PTO or xtal control
internal p/s - 115/230 v ac input 50-60 or 400 cps
T-474 522-0583-006 Transmitter, 2-30 Mc, AM/CW, 102 lbs
PTO or xtal control
42w output to 15-35' whip antenna
PP-1190 522-0584-006 Power supply for transmitter, 137 lbs
115/230 v ac input 50-60 or 400 cps
Optional Motor-Generators
PU-340(XN-1)/U -- 12 v dc input
PU-340(XN-1)/U -- 28 v dc input
PU-340(XN-1)/U -- 115/230 v dc input

Thanks to Jim Jones (W0NKN) @ Rockwell/Collins for the Collins P/N's! URC-8 is listed on various military equipment lists, which generally say that the receiver requires PP-1190. This is clearly not the case, as the receiver has an internal power supply (see pix below). The PP-1190 must, therefore, power the T-474. There's also an auxiliary DC Converter (187 lbs) that allowed running the set off a variety of DC and AC supply voltages.

The manuals are NAVSHIPS 92831 and 92927 (1957). Robert Downs (THANKS!) supplied the following additional info:
Old Number New Number Description
NS 92831 -- ? RADIO SET AN/URC-8(XN-1), IB 26 JUL 1956
NS 92927 0280-LP-417-2000 RADIO SET AN/URC-8(XN-2), IB JAN 1957

Anyone know the cross-reference for the 92381 document?

If you have ANY information about this receiver or the URC-8 equipment group, please send me mail

11/2012 - I obtained a copy of the NAVSHIPS 92831 manual - and will get it scanned soon

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Nick's June 2011 notes on R-627/URC-8 s/n 4 - Dual conversion, general coverage 2-30 mc in 4 bands.
One piece of info says 455kc 2nd IF and there are two empty mechanical filter sockets in the IF/BFO/AF module
There is a 70H-10 PTO (2.58-4.58 mc) as the HF oscillator.
I had been trying to figure out the conversion scheme and beyond figuring the PTO was multiplied as follows, had been scratching my head as I saw only one crystal socket that could act as the fixed LO for the 2nd converter.
Band (mc)   multiplier          PTO x multiplier (mc)
2-4                 x1                    2.58-4.58
4-8                 x2                    5.16-9.16
8-16               x4                   10.32-18.32
16-32             x8                    20.64-36.64

Then eureka, I finally found 4 xtals buried deep within the RF deck - this is a really compact bugger, but with flashlight and magnifier I managed to read the freqs. Here is my guess at the conversion scheme - using mid-band for illustrative purposes.
(freq in kc)
RF input     PTO x mult     1st-IF        XTAL     2nd-IF
  3000             3580              580        1035       455
  6000             7160            1160        1615       455
12000           14320            2320        2775       455
24000           28640            4640        5095       455

Yep, I found a couple of IF transformers with 4 coils/housing so it probably really does have a different 1st IF for each band.
And the extra xtal socket I had identified earlier is for the 100kc calibrator xtal.

Collins Interim Development Reports

Design Information - by Collins engineer Chan Rypinski - full article

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Specification Sheets

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Front view

R627.frontpanel.jpg (65806 bytes)

Serial number 4

R627.lf_tag.jpg (32878 bytes)

Serial number 4

R627.rt_tag.jpg (27000 bytes)

Rear view

R627.rearview.jpg (66099 bytes)

The receiver uses modular construction somewhat like that employed in the R-390A. There's an RF, IF/AF, and power supply module, secured into the mainframe with the famous green screws.
Top left view, showing RF module at bottom of photo:

R627.topleft.jpg (177470 bytes)

Top right view, showing IF/AF module at bottom of photo:

R627.topright.jpg (191576 bytes)

IF/AF and Power supply modules remove quite easily. Below are images of the partially emptied mainframe, with the PTO showing below the power supply module location. Also shown are the modules removed.

R627.topempt.jpg (171293 bytes)

Bottom view

R627.bottom.jpg (108960 bytes)

Left side

R627.leftside.jpg (58999 bytes)

Right side

R627.rtside.jpg (51739 bytes)

The PTO is a Collins 70H-10, which tunes from 2.58 - 4.58 Mc. The front panel contains a switch to select the PTO ("MO"), or one of four internal crystals, which in this receiver are at 2.58, 3.58, 4.33, 4.58 Mc. PTO tubes are a pair of 5749's. To the right is a close-up of the PTO nestled in the bottom of the rx. R627.ptocloseup.jpg (147497 bytes)
Inside of the IF/AF module. AF uses a pair of 6005's (6AQ5's) in P/P with 600-ohm output.
R627.insideimod.jpg (128030 bytes) R627.insideimod1.jpg (117032 bytes) - -