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Reviews For: Racal RA17L

Category: Receivers: General Coverage

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Review Summary For : Racal RA17L
Reviews: 12MSRP: 1200 - 2400
The Racal RA17 was a state of the art valve receiver when it was first introduced back in 1954. The Reciver that made Racal
Product is in production
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# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
KG8LB Rating: 2013-08-21
OK , Just OK Time Owned: 6 to 12 months.
Picked up a pair of these in Toronto . Both in great shape . Very nicely built , unusual but nice . Control layout is decent , sensitivity is about average for this class RX . The 35mm film "dial" gives decent bandspread . This RX is however , very cumbersome to move about ,even more so to service . Parts will certainly be an issue as well .
WA4053SWL Rating: 2013-02-07
Very nice receiver Time Owned: 3 to 6 months.
I have the RA17L and the R390A. The RA17L is far more suited to cruising up and down the bands than the
R390A. The scale calibration is much easier too. With the R390A for example you will wear yourself out long before it wears
you out thanks to the tedious stiffness of the tuning. Maybe the Collins is more better
suited to being parked on a channel for days at a time, eg one for the day
frequency and another for the night frequency with scheduled working, but the Racal is amazing to a SWL.
G8MOB Rating: 2011-06-18
One of the finest valved receivers ever made Time Owned: more than 12 months.
Pretty much everyone agrees that the RA17 was one of the finest valved receivers ever made and the 17L is the best of the bunch. I have four at home and so I'm biassed. They also probably contributed to my hernia but they were forgiven a long time ago!

However, we need to take a realistic and sanguine look at them in 2011. They are now 50 years or more old. When used by the military or the big commercial boys such as Cable & Wireless or the BBC they were well cared for. In the British Army REME inspections every 6 months achieved this. But for the last 30 years most of them have been kicking around in dealers' yards or cold garages or garden sheds (or worse) and many have been "got at" by the technically unwashed.

My advice when buying one is to walk away from any not in near pristine condition, unless bought for spares, and preferably with a manual. I have found that seller with a manual often knows quite a bit about the radio and has probably looked after it reasonably well.

But even when new these sets had some drawbacks:

1. The tuning rate is very fast at 100kHz per rev, but then so did the Collins 51J series and the R390. There is no easy way to improve this. I have tried fitting a Jackson epicyclic reduction drive but it has not enough torque to drive the mechanism properly. Re-greasing the ball bearings with Castrol "Molyslip" will improve the tuning feel, but don't grease the big bevel gears.

2. There is no SSB facility. They can be used to an extent by reducing the IF gain but the CW detector is not ideal nor is the RA17's IF selectivity. However, connect up a proper Racal SSB/ISB adaptor in good condition and my rating of 3 to 4 jumps to 5.

I have the RA98, RA121, RA218 and RA298. I prefer the RA121 because it has a nice fine tune (all of about 800Hz per rev) and excellent AFC with a carrier (full or reduced). It's an ideal way to receive AM on a fading flaky signal. It is also very good with CW or FSK by tuning the RA121 off by 800Hz to produce an 800Hz tone for CW or by 1.7kHz for an FSK signal.

The transistorised RA298 has excellent mechanical SSB filters made by Kokusai with a superb response and selectivity and a separate Plessey carrier filter of only around 50Hz. The carrier chain effectively deals with any frequency drift and gives excellent recovered audio quality.

The valved SSB adaptors will probably need a lot of new small components. I replaced all in the product detector and audio sections and OMG there was a major improvement. Practically all hum and extraneous noise disappeared leaving just low residual circuit noise. I also realigned the LC low pass and high pass sideband filters using a loaned modern R&S spectrum analyser called the FSP (a major performance I might mention) but the end result has been lovely crisp undistorted audio.

3. The Medium Wave performance is mediocre and there is nothing below 500kHz. The answer is to connect up the RA37 or the better RA137 VLF adaptor and you can then tune down to 12.5kHz using the "backwards" red scale on the film. These adaptors are excellent units and they work well with other radios tuning 2 - 3 MHz (but you will need a seperate 250V HT source unless used with the RA17 as it draws this supply from the 17). I have seen a special adaptor probably used by GCHQ to use the RA137 with the RA1792 receiver.

The RA137 will bring in weak VLF signals that a modern synthesised receiver would miss thanks to their bad synthesiser phase noise when tuning below 100kHz.

There are other adaptors that can build the RA17 into a most interesting system. The MA197B preselector provides awesome protection against powerful adjacent signals (such as on a warship). For example it will attenuate signals 5% or more off tune by up to 100dB and it can safely absorb up to 35 watts of signal input!

There were official modifications and variants for almost every use, typically for FSK, dual diversity reception, direction finding, spectrum analysis and frequency measuring.

There are a number of mods that will materially improve the RA17, such as to the AGC and fitting an S meter and a product detector.

One of my 17s shows what can be done. It was clearly the pet of the previous (deceased) owner, a proficient RF engineer. The chassis is of a RA17L but with the military F&E coax sockets replaced by SO239s. The front panel is for the North American RA17C-12 with a proper S meter, and the meter is wired up. The film scale lighting was radicaly redisigned using a strip of long life miniature lamps behind a diffuser for more even illumination and a green plastic sheet fitted in front of the film scale to improve the contrast and reduce the glare. He also fitted the very rare modules for the special external digital readout adaptor made as a special project by Norlin and giving a frequency readout to 10Hz.

I also use a DK-43 bargraph tuning adaptor on the 100kHz IF output to provide a spectrum display to 10Hz. The Racal MA1105 bargraph will also work but the DK-43 is better. [For details please my review of the Racal RA3701].

Overall, the 17 "bare" rates just about a 3, but with a lot of tarting up, replacing the components identified by other reviewers and fitting adaptors, the rating jumps to a well deserved 5. It's still one of my favourite radios of all time (but you will need a strong assistant to move it far).
VE7ZWZ Rating: 2011-01-09
Incredible Time Owned: more than 12 months.
A wonderful band cruser, great filtering and great selectivity. If you don't own one, and you would like a receiver that really works well, this is your answer. I have owned so many receivers, Collins, Hammarlund, RME, TMC, Modern Japanese receivers and so on. Nothing touches the Racal. Now go get one!
G3TSA Rating: 2010-02-02
RA17 MODS Time Owned: more than 12 months.
I have much experience on these sets.Look out for damaged filmstrip, check the Kc/s spins freely, with long use the worm and bevel gear wears.The meter is often open cct,with care you can insert meter guts from CB swr meter with superglue.
To double the audio output parallel the aux o/p tube with the regular o/p.Use 0.5 mf between anodes.
To vastly improve the agc , add a pnp emitter follower from -25 volt line so the 0.3 Mfd is charged much faster.
I stripped the bfo, and put a 6J6 osc/product detector super audio now.
When the preselector is tuned you should hear noise peak up ,particularly at hf ends with 50/75 ohm R on input.
Power input is 140 watts,I made choke input with - 25 obtained from fils , power reduced to 80 watts.HT at 210 volts.
G3VEL Rating: 2008-04-28
Great, but worth a few simple mods. Time Owned: 6 to 12 months.
I bought one on Ebay and had it shipped from the UK. All worked fine on switch on, with following minor observations: the BFO did not zerobeat at "0". The trimmer capacitor for this, C201, did nothing, for some reason. Eventually I found it was the attachment of the knob to the shaft that was wrong. Loosening a couple of grub screws and resetting fixed that.
The RA17 doesn't have a built in product detector, but injects a huge amount of BFO into the AM detector. As expected, like most boatanchors, this doesn't give the greatest sounding SSB. Also, AGC operation sounded dubious on SSB so you are motivated to use Manual. Also, the noise limiter operation was of questionable value, and had nil effect on SSB. All that, at least until I replaced the thermionic detector and NL diodes with 1N914's. For some inexplicable reason, all of the above criticisms then vanished. SSB sounds great; the noise limiter works on SSB - it doesn't distort SSB audio but completely kills those thunder crashes; and the AGC works perfectly on SSB with short attack and slow decay. You can just set the gain, turn on the AGC and listen to nets with multi-station overs at vastly disparate signal strengths in complete comfort. A possible explanation is that the diodes are used in megohm impedance circuits, and the designers may never have considered that the effective reverse current of the thermionic diodes is in the microamp range, while the 1n914's are in the picoamp range.

I replaced the thermionic diodes with 1N914s mainly to vacate two B7G bases to build in a product detector using two 6J6 double triodes, cheaply available on Ebay from Russia. I will add a switch to select between the normal AM detector and the product detector so I can get a good handle on the improvement, if any. This is an easy mod which I will publish when tested out.
The other thing is that the signal strength meter went O/C. The RA17L is the U/K version which just displays detector diode current, which tops out due to AGC action, or rapdily overloads without AGC, rather than the US version which has a true S-meter. Since a replacement 200uA movement is harder to find than a 1mA movement, modifying the circuit to give a better signal strength reading is also in order. Using the fixed level audio amp as a cathode follower to buffer the detector voltage and give some current gain allows less sensitive meters to be used, selecting resistors accordingly. I will publish this mod also when I have verified it.
Frequency accuracy was at first suspect, and I thought it was 1.3KHz off relative to my HP sig gen, which agrees with WWV. However, I just needed to give it a bit more warm up time. I looked away and looked back, and the built in 100KHz calibrator was then spot on with WWV, no adjustments needed.
I fell in love with this receiver in the 60's when it was the back-end of our satcomms low noise preamp testlab set up. Of course then, it would have cost 3 months salary. I probably paid the same for it today as it cost new then, but now it was only a mornings work HI!

If you used to do your own car repairs in the days when you could climb in under the hood and stand around the engine to work on it, you will be frustrated by today's vehicles. It's a bit like that with modern radio equipment too. Not so with the RA17. The construction is such that you get at just about everything you need to, so it is relatively easy to work on. The complete maintenance manual is on the web, on the 'BAMA mirror site, and can be downloaded in PDF form.
PA4TIM Rating: 2008-03-05
racal ra17l Time Owned: 6 to 12 months.
My first real radio, a very nice looking rather heavey and extremely well build rig. Inside everything is shielded and the alu chassis has all sort of chambers for the different receiver blocks. The sensitivity is good, a friend uses one with onley a 6 meter wire. I use a 2x25m dipole and have to be carefull not to overload it with to much signal. It is thanks to the wadley loop very stable. Tune in on a bacon, use the narrowest filter and 10 hours later you still hear the bacon. The preselection is very good. You onley need to learn to use it but after that it's great.
They are 19" rack mounted but there is also a cabinet. SSB and CW is a bit tricky, you have to use three tune knobs for that. The main band dial, the normal one and the VFO. But if you know how, it is very good. There is and optional SSB converter so you can hear SSB more easy. It covers 500Kc-30Mc. Under 500KHz it's rather deaf.There is an optional VLF module.
When you buy one, be sure it comes with an antenna connector and mains connector. Use a grounded plug . I first did not and I can tell you, it's not nice when you thouch it while holding an other not grounded tube set (there was 115V between them) . They are now all grounded. The MF filters are difficult to allign, you need a wobbulator for that. Often they are done on a scope of by ear and onley peaked on max. amplitude which makes the thing deaf.
A nice rig to own.
SWL1984 Rating: 2006-08-15
Superb Classic HF Radio Time Owned: 6 to 12 months.
I managed to find one thanks to eBay about six months ago. The seller was local luckily, so I drove home this 30kg beast in the back of my car.

They say it is too heavy and big, but I found it reasonable size and weight (thanks to my gym work out, I could lift this without much hassle - and it is not larger than my microwave oven in the kitchen), carried upstairs to my dungeon, and connected up.

This RA-17 is actually RA-17W model with somewhat different AM bandwidths - I read that RA-17W version is very rare on the internet. Along came with this unit is ISB121, which is a SSB decoder unit with ocilloscope, and all the cables and spare valves and the original manuals.

These units were in excellent condition and perfect working order. Having used last 6 months, I find this 50 year old set devine in built quality, looks, and most of all reception quality - stability, sensitivity and selectivity, which are superb. It beats my NRD 525, 515 and Yaesu FRG-7 in every aspect of HF reception everytime I compare.

SSB reception can be achieved via built-in BFO, which is great, but via separte ISB121, the audio quality and dynamic range is devine - nothing come close to it. Oh - another superb feature is its tuning mechanism - which is done with 2 large wheels, and smooth as Rolls Royce engine, and it can tune any freqency quickly and easily and accurately.

Now I got used to this radio, and every other radios feel like toys. Will never part with it. The best HF radio, I have come across so far. Only cons. I could think of is, it a bit heavy to take for mobile or portable, but I have Yaesu VR120D handy for that. And another minor point is that you need a good external speaker to get nice audio - I use pair of small HiFi speakers from the old dead Sony HiFi, and they work treats.
G1RHV Rating: 2005-05-07
Astonishing for its time Time Owned: more than 12 months.

Unbelievable build quality. Unaproachable ergonomically and aesthetically. The chassis is a work of art. Sound quality was good with a pair of headphones. Triple conversion Wadley loop - stability is awesome. Excellent selectivity offered by a range of filter bandwidths unmatched by almost anything since. Brilliant attenuator really helps the operator. Very quiet and sensitive rx. Lots of I/O connections at the back of the set. An enthusiasts dream.

Not so good:

Seriously heavy - Weighs 100 Lbs in its cabinet. Bear that in mind if you plan on moving house or even changing antennas....

Enormous footprint - you could lose most of a table under one.

There are very few RF technicians qualified to service these properly. Spares do appear from time to time...

Plessey connectors!

SSB wasn't a prerequisite in the 50's & 60's

For SSB look for an SSB adaptor or a 1772 with appropriate filters.

Speaker audio utilitarian - use headphones or an external loudspeaker.

I don't have one. (too big, need ssb etc..)
G4EDY Rating: 2004-10-27
Excellent! Time Owned: 0 to 3 months.
I have a rare ex R.E.M.E workshops model with a dark grey front panel. It is an excellent usable receiver, drift is non-existent, audio quality excellent and it is free of spuious responses with a huge dynamic range especially if you make proper use of the input attenuator. I use mine for Ham radio and broadcast SWL, it is wonderful to switch to 8kc/s bandwidth and listen to the 80m AM net. If you can find a good one then buy it!