Author Topic: Racal RA17 re-born : A trip down Memory Lane  (Read 6142 times)

Offline awemawson

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Racal RA17 re-born : A trip down Memory Lane
« on: January 19, 2019, 12:08:28 PM »
Years back I had a great interest in Communication Receivers - in fact I had quite a collection of what other followers of electronics would disparagingly call 'boat anchors'.

Before re-housing the workshop and moving here (11 years ago) I reluctantly disposed of most of them, but I could not bare to get rid of my Racal RA17. This receiver, made in 1957, is iconic. At the time it was probably the most stable communications receiver and was priced accordingly. Used in huge numbers by the armed services and many 'listening posts' it played a large part in our cold war defence 'snooping' on the Eastern Block.

Why was it so stable. Well it used the 'Wadley Loop' designed by Trevor Wadley (a South African) at the invitation of Racal, and uniquely used a single crystal generating many harmonics, to control two local oscillators whose drift would self cancel. (a VERY simplified description)

I don't remember when or even where I got mine, but I have found traces on the Internet of me asking questions back in 2002, so it was before then !

Now it's been packed up for those 11 years. The capacitors and resistors in these sets are well known not to age well, and I do recall dimly from before I packed it up that it would benefit from some TLC - leaky capacitors and resistors changing value all contribute to reducing sensitivity and selectivity.

I've decided that at last I must get this unit back into commission, but sadly I no longer have the RF test gear that I did, and this set has some very complex filter networks (100 khz, 37.5 & 40 Mhz) that need sweep generators to set to the accuracy demanded.

So, biting the bullet, I'm planning  to 'out source' the work to one of the very few people able to do it. This will include replacing all electrolytic capacitors, all paper capacitors above 4.7 nF, replacing all carbon resistors, and re-aligning the filter units.

It's had a few 'modifications' where non original sockets have been substituted for more common ones, and those mods will probably be reversed if possible.

To whet your appetite have a few pictures taken today when I pulled it out of the eaves storage where it's been all these years:

Andrew Mawson
East Sussex

Offline hermetic

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #1 on: January 19, 2019, 12:56:12 PM »
I used to fiddle with communications recievers when I were a lad, that looks like a beauty! I lived at the village shop in Langtoft, East Yorks, and well remember our lovely paper delivery lady, ariving to sort the papers on the dining table, where I was tinkering with a bare chassis, I casually wander over and picked it up, having forgotten it was still on.....................How she laughed!! I must have looked like Michael Jackson dong the dance for "Thriller" It bloody hurt!
Man who says it cannot be done should not disturb man doing it! https://www.youtube.com/user/philhermetic/videos?

Offline awemawson

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #2 on: January 19, 2019, 12:59:21 PM »
So the next thing to work out is how to transport this megalith (97 lbs not including the 'desk mount' case!) the entire length of the UK while retaining some confidence that it won't be smashed to smithereens  :bugeye:

Meanwhile have a fragment of the circuit showing a few of the pesky filters that need aligning :
Andrew Mawson
East Sussex

Offline Pete.

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #3 on: January 19, 2019, 02:30:08 PM »
I shipped an unused vintage 1940's tilley floodlamp to Australia without it getting damaged. The buyer stated that he didn't care how much it cost him so long as it arrived un-damaged. We bought a double-thickness cardboard box and a whole roll of bubble wrap. Of course that thing only weighed about 8-10kg not 97, but the concept is the same. Sturdy box and loads of bubble wrap to insulate it then parcel-strap it to a mini-pallet so it'll always remain right side up.

Offline awemawson

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #4 on: January 20, 2019, 05:51:08 AM »
A bit more progress: I've managed to lug the beast out of it's eaves storage, down the stairs, into a wheel barrow, across the farm yard and into the workshop. Poor thing looked so forlorn sitting in a wheel barrow  :(

I've also 'discovered' a nice ready made pallet complete with pallet sleeve and lid. To reduce the weight from 97 lbs to 67 lbs I've removed it from the table top case. This also has the effect of increasing the amount  of packing I can fit between it and the pallet case.

At Pete's suggestion I've ordered a huge roll of bubble wrap. It will be swathed in the stuff as an independent parcel, then strapped down to the floor of the case before final stuffing when the sleeve is installed.

A bonus when I removed it from the case, was to find two copies of the manual tucked down the side of the RA17 - I do vaguely remember hunting around and sourcing them all those years ago.

Attached to the internal racking of the case was a label dated  29/1/65 showing it had been inspected at the Admiralty Surface Weapons Establishment further confirming it's nautical history.

One of the issues with these sets was the moving coil meter that was fitted. Made by Ernest Turner, the very fine wire of the coil was originally varnished with a varnish that over a long period became corrosive and dissolved the coil - testing mine it seems to work, so that's one hurdle over come  :thumbup:

Thumb twiddling time now until the Bubble Wrap arrives
Andrew Mawson
East Sussex

Offline PekkaNF

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #5 on: January 20, 2019, 07:53:05 AM »
May I suggest soft building styrofoam sheet between boxes or inside the first box. Bubblewrap work very well on lightweight objects, but not so well with heavy pointed behemont.

Once I needed to ship a designer glass picher to Denmark, I build a cradle out of styroxfoam with hot wire cutter and glued some ply wood stringers tactically to keep the whole thing together and designed it to be easy to unstall with few wood screws wrapped over red tape and note to say "remove screws under red tape". It was greatly appreciated: I got the message that before reading the note big tools were carried to table:)

I don't know how much extra it cost there to send it "Fragile, this side up and no gargo atop of it". Recommed screwing the device on slightly larger subframe/pallet, that will protect it from shifting.

Tilt and schok indicators are not that expensive and seem to put some extra care in parcel handling.

Offline awemawson

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #6 on: January 20, 2019, 08:05:44 AM »
Thanks Pekka, yes the foam sheet is already to hand  :thumbup:

I always have a slight hesitation marking things as fragile etc suspecting that some oafs use it as an invitation to bounce things !

Hopefully this 'outward' journey is less critical than the 'return' when it's all been set up properly.

I've just been reading the maintenance manual, and although I've done this sort of thing before when I had the right kit, I'm glad I decided to outsource it  :clap:
 
Too large to upload but it's here:

http://www.vmarsmanuals.co.uk/archive/1979_RA17_Operating_and_Maintenance_Manual.pdf
Andrew Mawson
East Sussex

Offline PekkaNF

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #7 on: January 20, 2019, 08:22:05 AM »
Here you pay extra fees on "Fragile" and "this side up" etc. and they mark them.

If I mark something similar and don't pay, they will probably play elephant poolo with forklifts with it. Good packing and ruggerizing is good, but I like to hide that inside the carboard box that has some "crumple zone", because if it looks too sturdy, it will end up under everything and with my luck someone will palce a pallet full of anchors or anvils atop of it.

Pekka

Offline Pete W.

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #8 on: January 20, 2019, 09:58:25 AM »
I remember the RA17 but by reputation only, it was an equipment to lust after.  I started with an R1155 and later acquired a Hallicrafters 'Sky Rider Defiant', I think it was labelled 'SX24'.  Octal-based valves ('toobes') and about the same age as me but it worked well!!  Many years later, I met a Radio Amateur who lived in Wiltshire and had every model of Hallicrafters communications receiver!  I didn't visit him for that reason - I sold him a Specto cine projector to complete his other collection!!!  It was a Specto 'Analytic', 16 mm and capable of 16 fps, 2 fps or stop!!

The main relic I have from my Amateur Radio days is a Trio (aka 'Kenwood' ) R1000 receiver.  It has developed a fault in storage - I don't have time to repair it myself and haven't yet found anyone else I'd trust with the job!!

At one stage in my career, I used to make occasional visits to the 'Admiralty Surface Weapons Establishment'.  The people I visited there were very clever - funny how it's the really clever ones who are usually the ones who are generously helpful.  This was before the Scientific Civil Service was privatised.  There was a dedicated turn right lane in the road outside the establshment's main gate.  The letters 'ASWE' were painted on the road surface of that lane to indicate its purpose.

That road inscription was updated when the establishment was renamed 'Admiralty Radar & Signals Establishment'.
I believe those letters actually lasted two or three days!   :D   :D   :D   :D   :D   :D 
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest design change-note!

Offline seadog

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #9 on: January 24, 2019, 06:48:31 AM »
I was watching "The World is not Enough" last night. I'm pretty sure there were a pair of RA17s in the scene where M's locator beacon is picked up.

Offline awemawson

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #10 on: January 24, 2019, 08:43:16 AM »
Sadly a lot got bought up as film props. A while back, a large organisation that shall remain nameless (or I'd have to shoot you) disposed of lots of them when they replaced them with the later synthesiser models. 18 months later they were trying to buy them back as the performance was no better but the reliability was atrocious !

So the bubble wrapping having arrived, I set to pack up the RA17 for it's journey to Scotland.

First I sealed off the chassis with green plastic corrugated sheeting that is used to let milk bottles sit on a pallet (Handy having a milk maid as a friend  :ddb:
)

Then I taped thick expanded polystyrene sheeting on all surfaces and a triple layer on the front. (Expanded sheeting recycled from that Portakabin roof that I replaced). Then numerous layers of the bubble wrap were put on before laying into the crate.

Once settled on the pallet floor (which is close boarded) I tightly packed more expanded polystyrene around it so there was (I hope) no possibility of it sliding about) before putting the lid on and banding it down with my ratchet strapper.

Due for collection tomorrow.

Andrew Mawson
East Sussex

Offline seadog

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #11 on: January 24, 2019, 11:54:49 AM »
I guess it stands a fighting chance of arriving in one piece  :D

Offline awemawson

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #12 on: January 30, 2019, 11:33:21 AM »
Well the packaging seems to have worked, in that the RA17 has arrived in Scotland and is on the repair bench, opened up for a first investigation.

There are one or two wiring oddities that have been applied over the years and will be removed, for instance that bit of white co-ax shouldn't be there - it runs from the input to the 40 Mhz filter to an external socket that was originally the 100 kHz i/f output. Also the terminal strip that takes outputs for the audio and the one that interfaces to the optional low frequency converter (RA37 or RA137) has been altered and will be returned to original.

Just as well, as I've just sourced an RA137A-1 which is currently in transit to me from deepest Spain  :bugeye:

. . . updates will follow
Andrew Mawson
East Sussex

Offline seadog

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #13 on: January 30, 2019, 12:43:53 PM »
Hoping to do some LF DXing, Andrew?  :lol:

Offline awemawson

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #14 on: January 30, 2019, 12:56:17 PM »
Yes those submarines in the South Atlantic had better watch out  :clap:
Andrew Mawson
East Sussex

Offline tom osselton

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #15 on: January 30, 2019, 01:15:53 PM »
Firing torpedos from the loo are we? :coffee:

Offline awemawson

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #16 on: February 04, 2019, 07:29:33 AM »
Today ParcelForce brought me the RA137A-1 LF adapter - all the way from Alicante  :thumbup:

It seems unharmed by the experience, but the seller is on the naughty step as the special Plessey 3 pin mains plug and lead were not included, despite being illustrated and (thank goodness) specifically mentioned by me as a note in the Paypal transaction. Hopefully he'll do the decent thing and send it on, but this is where 'pay after receipt' with Paypal comes into  play  :ddb:

A brief examination shows it's not in too bad condition. The complicated tuning cord / pulley / drum arrangement can lead a grown man to tears if the cord comes adrift, but this one is intact.

No signs of ham fisted poking about in side thankfully - in fact there are no signs of components having been replaced in the past, which is a 'good thing'. As would be expected, measuring a few random carbon resistors  they have aged somewhat and are in the main higher by 20% than they should be. I will probably replace them all, along with most of the capacitors.

Now I need to source a replacement Table Top Case that will take both the RA17 at 10.5" and the RA137A-1 at 3.5" so a total of 14" in a 19" rack - I think that's a '7U' an '8U' case but stand to be corrected. (I was wrong!)

. . . can't try it of course until the RA17 is back from it's visit to the health spar and returns refreshed.

« Last Edit: February 04, 2019, 08:20:47 AM by awemawson »
Andrew Mawson
East Sussex

Offline Pete W.

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #17 on: February 04, 2019, 08:47:29 AM »
Andrew,

I bought a three-pin Plessey Mk IV free socket from an eBay supplier to be able to connect mains to a CT signal generator.  I should have the PayPal receipt archived somewhere - if I can find that, it'll tell me the supplier's eBay ID.

I'll have a dig in case your Iberian bloke doesn't do the right thing.  (I take it you've thoroughly checked all the packing material!!) 
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest design change-note!

Offline Pete W.

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #18 on: February 07, 2019, 04:22:04 AM »
Having trundled my way through about six years of PayPal receipts, I found no trace of the Plessey Mk IV connector transaction - maybe I paid him with a cheque.

Sorry!! 
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest design change-note!

Offline awemawson

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #19 on: February 07, 2019, 04:29:25 AM »
Cheers Pete. There are a couple on eBay at the moment (on my watch list) but the seller 'says' he's sending the missing cable.

I've given him a time limit before I cancel the Paypal transaction to concentrate his mind  :poke:
Andrew Mawson
East Sussex

Offline awemawson

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #20 on: February 07, 2019, 05:02:01 PM »
Amazing how a little persuasion works - he's come back with a tracking number  :clap:
Andrew Mawson
East Sussex

Offline awemawson

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #21 on: February 18, 2019, 05:26:35 AM »
My RA17 has risen to the top of Ian's 'In-Tray' and he has started the investigation prior to replacing all the resistors and capacitors.

There are the expected signs of overheating and charring - the large wire wound resistors in the PSU will be replaced by metal clad chassis mounted ones, which was an official Racal modification back in the day.

From the components installed it seems that it last had it's capacitors replaced some 40 years ago so this will be at least the second time.

In one instance (in the 2nd mixer) one of the original capacitors is still in place but the wrong place! Supposed to be across the valve heaters but would seem to had been originally mis-wired at manufacture. Apparently Ian has seen this same error before, but on an RA117E (which is basically the same as the RA17) so Racal had a hole in their QA !

Andrew Mawson
East Sussex

Offline awemawson

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #22 on: February 20, 2019, 08:37:02 AM »
More progress reports: Ian has been concentrating getting the mechanical side of things sorted before going on to the component replacement and re-alignment.

He has replaced the none standard sockets on the rear (mains input, aerial input and IF / LO output co-ax's) but the main thing was that he found that the mode selector 'system' switch was completely wrong, the original three wafer one having been replaced by two wafer one. Fortunately he had a correct one to install.

. . more to follow . . .
Andrew Mawson
East Sussex

Offline seadog

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #23 on: February 20, 2019, 02:01:57 PM »
Yaxley switches, Loved them.

Offline awemawson

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Re: Racal RA17 re-born : A trip down Memory Lane
« Reply #24 on: February 20, 2019, 02:19:07 PM »
Yes always fun taking apart and getting them back together  :clap:

I put out a plea on a vintage radio forum for the missing louvered metal cover (the one I substituted a green corrugated sheet for when packing) and it's produced results and also an RA63 sideband adaptor to match so that adds another aspect to my interest. All I need to track down now is the RA66 panoramic adaptor with its MA251 buffer amplifier to get back set up as I wanted decades ago  :lol:

Andrew Mawson
East Sussex