MadModder

The Craftmans Shop => New from Old => Topic started by: awemawson on January 19, 2019, 12:08:28 PM

Title: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson 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:

Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: hermetic 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!
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson 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 :
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: Pete. 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.
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson 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
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: PekkaNF 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.
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson 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
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: PekkaNF 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
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: Pete W. 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 
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: seadog 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.
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson 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.

Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: seadog on January 24, 2019, 11:54:49 AM
I guess it stands a fighting chance of arriving in one piece  :D
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson 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
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: seadog on January 30, 2019, 12:43:53 PM
Hoping to do some LF DXing, Andrew?  :lol:
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on January 30, 2019, 12:56:17 PM
Yes those submarines in the South Atlantic had better watch out  :clap:
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: tom osselton on January 30, 2019, 01:15:53 PM
Firing torpedos from the loo are we? :coffee:
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson 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.

Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: Pete W. 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!!) 
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: Pete W. 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!! 
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson 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:
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on February 07, 2019, 05:02:01 PM
Amazing how a little persuasion works - he's come back with a tracking number  :clap:
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson 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 !

Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson 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 . . .
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: seadog on February 20, 2019, 02:01:57 PM
Yaxley switches, Loved them.
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson 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:

Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: Will_D on February 20, 2019, 05:02:39 PM
More progress reports: Ian has been concentrating getting the mechanical side of things sorted before going on to the component replacement and re-alignment.
Seem to remember a brand called "Make-a-switch"
It had 12 positions on each switch wafer, so you could have 1 x 12, 2 x 6, 3x4, 4x3 combinations plus the mechanical stop plate(to limit movement) , and you could stack up a lot of wafers.

Sort of rotary switch Meccano!!

I had a lot of them salvaged from old equipment.
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on March 28, 2019, 02:43:29 PM
Ian has sent me a couple of updates in the form of .pdf documents which I'll attach one by one due to size limitations


.. . . .whoops it seems that they are both too large - I'll see if I can pull bit's out and post them  :doh:
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on March 28, 2019, 04:17:23 PM
And the second report
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on April 02, 2019, 10:04:52 AM
Now I have received Ian's third report as a .PDF 8.8 mByte long, but oddly if I save each of the two pages that it consists of using 'PDFCreator' they are each less than 900 kByte - same happened when I did the previous two reports  :scratch:

Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: David Jupp on April 02, 2019, 10:46:18 AM
He probably generated the original using Microsoft Print to PDF - it's notoriously inefficient.
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: seadog on April 02, 2019, 10:59:32 AM
That's a very thorough refurb. I've just been looking on line and seen an 1154/1155 that he refurbished. Fantastic work.
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on April 02, 2019, 11:45:00 AM
That's why I chose him - he has a very good reputation and his refurbished radios command a premium price from the cognoscenti. Particularly with the RA17 series he has a lot of experience getting them back to at least as good a performance as when they left the factory. His next report hopefully will show the careful work getting the correct pass band shape of the complicated filters.

Mind you it's bankruptcy territory paying him  :bugeye:
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: seadog on April 02, 2019, 12:16:15 PM
I see that the most recent prices he's posted are for 2015. Has inflation taken its toll? 
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on April 02, 2019, 12:26:49 PM
Time will tell  :bugeye:

(but actually his price is quoted as of Jan 2018)
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on April 20, 2019, 01:02:21 PM
Ian has finished waving his magic wand over the RA17 and it is looking SPLENDID from the pictures that he has sent me.

Not seen it yet as I've asked him to do a similar re-furbishment on my RA137-1 LF attachment - waiting his response.

By total co-incidence I came across a mystery parcel on the shelf in my welding shop today, and according to the label it contains a good RA17 1ST VFO unit wrapped up by me 22/10/2002 and charged with silica gel desiccant.
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on April 21, 2019, 04:41:35 AM
So I'm glad to be able to report that Ian has agreed to breathe his magic over the RA137a-1 LF converter which undoubtedly needs the same attention to the aged capacitors and resistors, and a bit of alignment - though it is a far simpler affair than the RA17 itself.

Up early this morning (as loads of family descending on us soon for Easter) and packed it up sandwiched between a pair of sheets of plywood hopefully to  protect it from the ravages of couriers in transit. Awaiting collection on Tuesday after the Bank Holiday.
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: Pete. on April 21, 2019, 05:25:40 AM
I can't imagine the hours that's gone into that refurb. I don't suppose there are many people about now who could even do it.

The before and afters look amazing, along with the comprehensive report.
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on April 21, 2019, 05:29:13 AM
Yes he turns out good work.  :thumbup:

He enjoys what he does, similar to me titivating various bits of CNC machinery, and certainly if one didn't enjoy it it would be quite a slog.
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on April 30, 2019, 04:41:49 AM
Well I've been and gone and done it again   :clap:

An RA218 independent side band adaptor for the RA17 turned up on eBay and I won it last night. These are fairly scarce these days so although this one is not in prime condition I grabbed it.

The RA218 makes interfacing RTTY (radio teletype) equipment a doddle, and since that is what got me into computers back in the 1970's it's a bit of re-living past experiences.

The RA218 contains some unusual glass enveloped crystals - the most rare of them - an 18 kHZ -  SEEMs to be present, but the others are contained in a crystal oven so the pictures cannot tell me if indeed they are there. I can tell from the photos that two valves , VT11 & VT12, are missing from their screening cans, but they are only 12AT7's used as audio output stages for the upper and lower sidebands. 12AT7's are still easily available at sensible prices (amazingly RSComponents stock them !!!) unlike many other valves which have become trendy in the "pretentious audio" world!

This time I have totally cheated, and have arranged for the seller to send it directly to Ian who has again agreed to wave his wand over the unit. He has one of these adaptors in his own RA17 / RA117 set up, but when he got it that rare 18 khz crystal was missing and he is running on a jury rig of a different crystal and a TTL divide chain!

So that's two RA17 adaptors from me on his 'to do' list  :ddb:
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: seadog on April 30, 2019, 05:30:04 AM
12AT7's are still easily available at sensible prices (amazingly RSComponents stock them !!!) unlike many other valves which have become trendy in the "pretentious audio" world!


Call them an ECC81, plate the legs gold and put the name Mullard on the envelope and you are talking silly money.

I sold 5 untested, other then the heaters, mixed ECC valves in 2015 - 50  :beer:
They came in a mixed box that I bought from a car boot for 15. I must have taken well over 100 out of that box tp date  :thumbup:
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: Will_D on April 30, 2019, 06:02:07 PM
Weren't ECC81's common as chips in TVs? I had a box full!
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: seadog on April 30, 2019, 07:59:09 PM
Indeed they were. The EF80 was another. I sold three dozen of them, untested, to a chap in Malaysia. It cost more to post them than he won them for (7-55). It was interesting packing them.
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on May 01, 2019, 03:56:59 AM
When I was at school I was befriended by a chap in the TV shop in the town, and can remember cycling home one day with my push bike saddle bags FULL of EF80's, PL84's and ECC81's that had been pulled from sets that he was scrapping. Back then before common sense had been banned and children were allowed to DO things we had a Radio Club at school where we regularly dived into the back of mainly Black and White but very occasionally colour TVs.

But then, in the CCF signals section at school we had a C52 transmitter that we regularly netted with other school CCF's, and the aerial for that TX would kill any careless sparrow that put a foot wrong  :clap:

Children these days miss out on SO much - bending plastic just isn't the same.


Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: seadog on May 01, 2019, 05:40:38 AM
What was the C52, Andrew? I had a C50 for a while which I ended up scrapping due to lack of interest and space  :(   :Doh: :doh:
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on May 01, 2019, 08:26:37 AM
C52 was a 19 set on steroids - C denoting made in Canada
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: seadog on May 01, 2019, 10:21:56 AM
Very nice. I've never heard of that rig before.
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: Will_D on May 01, 2019, 02:43:04 PM
But then, in the CCF signals section at school we had a C52 transmitter that we regularly netted with other school CCF's, and the aerial for that TX would kill any careless sparrow that put a foot wrong 

I ended up as signals sergeant in our CCF. Our call sign was 4Charlie (Llandovery College in Carmarthenshire).

We used a 19 set but with some extra booster/amplifier. We managed QSL contacts with a lot of public schools even oin Scotland.

We also had a mobile system - a 19 set and some very large lead acid batterys mounted on a large hand cart. A couple of junior ranks had to push this round the back roads around the school. That was c/s  Foxtrot4Charlie.

I bought a 19 set with PSU etc and managed to bring it home on a double decker bus and carry it the last half click to my parents house. I built a mains power supply for it in the old rotary converter box and so another F4C was alive in Abergavenny. I took it to Salford when we bought our first house and somehow lost it!!

Thanks for the memories Andrew
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on May 01, 2019, 03:00:15 PM
One memorable CCF camp was at a place called 'Whiteworks' on Dartmoor - down a very long track just opposite the prison. One day on exercise I had to establish 'base camp' on top of a local 'high bit' called 'Gutter Tor' - iirc I had an 18 set and the other platoons were using WS38's. Managed to erect an aerial mast and got everyone 'netted up' - all was working extremely well until some other 'mob' broke in on our frequency. I (aged probably 15 or 16) ripped into them questioning their forebears and pointing out how they had totally ignored standard operating practice (ie listen before swamping people). I Assumed they were another school CCF platoon.

Oh no - they were regular Army  :bugeye:

Didn't stop their CO flogging all the way up Gutter Tor to make an abject apology  :clap: :clap: :clap:

Then the thunder storm broke and he helped me strike the aerial mast  - oh the power of the spoken (irate) word.

 . . . . I suppose I was bolshy even then  :lol: :lol:


https://en.wikipedia.org/wiki/Whiteworks


https://getoutside.ordnancesurvey.co.uk/local/gutter-tor-west-devon


Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: Will_D on May 01, 2019, 04:25:15 PM
What were those little mobile sets called? Were they 88's?

 They used a 22v and 1.5 dry battery combo and fitted into two belt pouches
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on May 01, 2019, 04:54:04 PM
Yes WS88 - there were two variants usually differentiated by   the lower 4 channel sets being painted green, and the higher ones were black iirc Very nicely made and crystal controlled.

Post WW2 they were more Korean War vintage - totally immersible hermetically sealed and they floated! I had several pairs of them back in the  1980's. When demobbed they had to be made inoperable so they cut off the pressel switch that was on an umbilical cord which was used to switch from receive to transmit. Every now and again the pressel switches turned up in the junk shops in Old Compton St and Little Newport St so you could re-unite them  :clap:

My first home made inverter was to power those sets - as you say 1.5 volts for heaters and (not 22v) 90 volts for the anodes. I could never get the invertors to be electrically noise free so the set whined !

*** Later edit, that must have been late 1960's not 1980's  :bugeye:
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on May 03, 2019, 08:12:07 AM
Well I'm pleased to be able to report that the RA218 ISB adaptor has arrived with Ian in Edinburgh direct from the eBay seller who is in Manchester, thus saving bouncing up and down the UK.

Ian tells me that all the rather rare and special glass encapsulated crystals are are still present - they often get pilfered as spares - and we've located replacements for the two circular Plessey connectors on the rear panel that had been replaced by 'chocolate blocks', so some degree of originality can be restored :)

I thought that I'd located a suitable 19" rack  locally to house all this gear but modern racks only seem to take 400 mm front to back depth  behind the panel - the RA17 needs 480 mm :(

Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: AdeV on May 03, 2019, 01:29:22 PM
A server rack should do you fine - they're usually 800mm front-to-back, plenty of room for 480mm deep kit.

As an example: https://www.ebay.co.uk/itm/12u-Server-Rack-cabinet-600-W-x-800-D-x-634-H-Glass-Front-Door-Flat-Pack/191869787799
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on May 03, 2019, 05:26:49 PM
Thanks Ade,

I've looked on line at a few server racks, and the few that give the vital dimension between the front and rear vertical rails all have proved to be no more than 400 mm :(

That one may be deeper I'll ping them a question

Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: Pete W. on May 04, 2019, 05:31:04 AM
Hi there, Andrew,

Should you decide to home-brew a 19" rack, I have an Imhof catalogue somewhere in my filing 'system' that might have any dimensions you need.

My last experience with 19" hardware was complicated by ensuring consistency between the mounting screws and the cage nut - the options were 0 BA, " BSF or M6.  That's the recent 19"-lite, the traditional was 0 BA tapped holes in good old solid mild steel angle.  Imhof must have had a standing order with the tap manufacturers! 
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: awemawson on June 06, 2019, 10:29:06 AM
Ian has contacted me today with the good news that he has completed the refurbishment and re-alignment of the RA137A-1 and included his report which I've split into three pages and attach.

It's all looking squeaky clean  :thumbup:
Title: Re: Racal RA17 re-born : A trip down Memory Lane
Post by: russ57 on June 07, 2019, 05:26:07 AM
I bought a 19" rack a long time ago. Turned out it had been modified to make it 21" by liberal application of 'very hot' metal glue.

I can't remember now how I removed the weld  to return to a (bolted) 19", but I know I didn't own an angle grinder at the time.


Russ