EB5AGV's RA-117 Pictures and Technical Information

Keep them glowing!

Here you have some pictures I have taken from my RA-117, along with some technical data about it. I'll add periodically more information to this page, so stay tuned for changes!.


GENERAL VIEW and BASIC INFORMATION

Racal RA-117 Front Panel Racal RA-117

From the RA-117 manual: 'The Communications Receiver Type RA-117 has been designed for use as a general purpose receiver which will provide a high order of selectivity and stability. The receiver covers a frequency range from 1.0 to 30.0Mc/s... The chassis and major modules are of cast construction thus ensuring maximum rigidity and effective electrical screening.'

The RA-117 is very similar to late RA-17 series (RA-17L) externally, but has important differences in its circuitry, as an added IF stage (it is a four conversion receiver) and lots of tube (valve) and component changes. Anyway, the main characteristics, as the Wadley frequency drift cancelling loop remains. Just as a curiosity, I had the receiver on the workbench for two days before realizing I had a RA-117 instead of a RA-17L...

This receiver is a big one: 10 1/2" Height x 19" Width x 20 1/8" Depth (it is deeper than any of the 19" receivers I have in my shack!). And, consequently, it weights a lot: 62 lb (28 kg). All of this WITHOUT cabinet!. Definitely, not a portable ;-).


IDENTITY TAGS

RA-117 front panel tag Front panel tag

RA-117 rear panel tag Rear panel tag

RA-117 MOD record tag MOD record tag

This one is a military unit, as you can see from the front panel tag. Serial number is 0229. And manufacturing date is December 1962, as in the label you can read 'TM' being 'T' year 62 and 'M' December (thanks are due to Robin Filby for this information).

I would like to add a page of RA-17 and RA-117 units information, similar to the one in the R-388(A) pages. So, please, if you own any of these nice receivers, please, let me know.


TUNING SYSTEM

RA-117 Dial RA-117 dial

Tuning is very easy with the RA-117, as you have a big megacycle knob, which electronically (not mechanically, as in most other old receivers, so it is very smooth; think about the R-390(A), R-388(A), SP-600, ... Not so smooth!) selects the 1Mc band you want to work and then you have another big kc knob, which selects, by means of a large film scale (efective lenght is 145 feet, i.e. 6 inches of scale corresponds 100kc/s), the kc component of the desired frequency. Frequency increments remain constant over the entire range of the receiver.

RA-117 kc dial mechanism detail RA-117 kc dial mechanism detail


FRONT PANEL

Here you have some close pictures of the panel S-meter and controls. Most of them are self-explaining!.

RA-117 S-meter S-meter

RA-117 function selector Function selector

RA-117 BFO control BFO control

RA-117 bandwidth control Bandwidth control

You can select six different IF bandwidths. Filter data is detailed in the table. Wider bandwidths use L/C circuits, and 0.1 and 0.3 kc/s bandwidths are obtained with crystal-lattice filters.

RA-117 Selectivity Options
Position BW(-6dB) BW(-66dB)
100c/s 0.10kc/s less than 1.5kc/s
300c/s 0.3kc/s less than 2kc/s
1.2kc/s 1.2kc/s 8kc/s
3kc/s 3.0kc/s 15kc/s
6.5kc/s 6.5kc/s 22kc/s
13kc/s 13kc/s 35kc/s

RA-117 RF range RF range

By means of the RF Range control, you can select two wideband (not tuned) inputs at 2000 and 75 Ohm input impedance, and five double-tuned bandpass inputs.


RA-117 vs RA-17

RA-117 top view RA-117 top view

If you are familiar to the RA-17 series, here you can see the main differences between them and the RA-117. At the left side of the picture, you have the second VFO unit, which in the RA-117 is smaller, because one previously tuned stage is now fixed. But all the components enclosed in the red line are additions to the RA-117, including the new 1.6Mc/s IF stage and a 2-3Mc/s band pass filter.
RA-117 added components and 2nd VFO Added components and 2nd VFO

In the enclosed zone, you can see lots of coax wiring. These coax go to BNC connectors, and let you select, by doing the proper connections, the use of internal or external reference oscillators and second VFO.

1Mc/s crystal 1Mc/S crystal

Rear panel BNC connectors Rear panel BNC connectors

Another very interesting feature, also found in late RA-17s, is the 1W/3Ohm audio output, instead of the former 50mW/3Ohm. Now the front panel small speaker is more useful and, adding an external common 4Ohm speaker, you have a nice audio output, without any amplifier.


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