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Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
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6th Aug 2020, 12:38 pm | #1 |
Hexode
Join Date: Jul 2009
Location: Wokingham, Berkshire, UK.
Posts: 437
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R210 Larkspur receiver
Always fancied one of these, and managed to pick one up for £40 plus external PSU and audio amp, with the film scale in a can and the workshop manual.
Externally a bit shabby but internally almost like new. Refitting the film scale looked a bit daunting as the set requires a fair amount of dismantling, but with the book, pretty easy. Usual problem of solidified grease and oxidised oils, all cleaned up and lubricated using moly based grease and modern oils. Needed to be quite dexterous really, with ideally 3 hands to do the scale but managed pretty well at third attempt, and refitted it correctly as per book. Reassembled the unit powered it up and set the film scale centrally to the cursor at 2.5 MHz injected 2.5MHz and it was pretty close, reasoned that the alignment hadn't been touched so adjusted the flexible coupler to match scale to frequency. Tried on all other bands and very close, so a quick twice of alignment probably called for after 60 years. Whilst on the bench I managed to knock the RF amp valve and the signal dropped in level. Tapping around the signal varied in level accordingly. Looking at construction I thought Oh *** need to take the RF unit our again. Not so, someone had put a lot of thought into the construction, as all screening panels were easily removable (excluding myriads of screws). Once panels were removed and the unit powered up, it was easy to trace the problem which was a non-soldered joint on the RF valve base cathode connections. Re-soldered it powered it up and bounced/dropped the unit around the bench - perfect. How this joint had survived over 60 years I don't know as the exterior, as I said, looked knocked about a bit Left it running all day - minimal drift uncased so reasoned all good. Now to make a proper PSU for it, might be able to fit it inside the case after taking out all the vibrator PSU bits and pieces, we shall see. A beautifully made unit, easily serviceable - you can see why military equipment costs so much. A pleasing couple of days work the satisfying results. John |
6th Aug 2020, 2:15 pm | #2 |
Nonode
Join Date: Dec 2012
Location: Stockport, Greater Manchester, UK.
Posts: 2,105
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Re: R210 Larkspur receiver
Good success story! Just looked on Radiomuseum to see one, looks delightful, but why would NATO want a vehicle-mounted transceiver to cover Medium Waves
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- Julian It's good here |
6th Aug 2020, 2:22 pm | #3 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,871
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Re: R210 Larkspur receiver
For when they stopped for a brew up?
David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
6th Aug 2020, 3:47 pm | #4 |
Heptode
Join Date: Mar 2008
Location: Forest of Dean, Gloucestershire, UK.
Posts: 648
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Re: R210 Larkspur receiver
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6th Aug 2020, 5:42 pm | #5 |
Hexode
Join Date: Jul 2009
Location: Wokingham, Berkshire, UK.
Posts: 437
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Re: R210 Larkspur receiver
It is not a transceiver but a standalone 24 DC powered receiver with vibrator run internal PSU and phone output only and covers 2-16MHz in 7 bands as follows:
2.0 - 3.0 3.0 - 4.5 4.5 - 6.8 6.8 - 9.1 9.1 - 11.4 11.4 - 13.7 13.7 - 16.0. John |
6th Aug 2020, 5:46 pm | #6 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,871
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Re: R210 Larkspur receiver
They'd have to listen to the world service, then.
David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
6th Aug 2020, 6:31 pm | #7 |
Nonode
Join Date: Dec 2012
Location: Stockport, Greater Manchester, UK.
Posts: 2,105
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Re: R210 Larkspur receiver
Ulp, I see it now Quote from Radiomuseum
1. 2 to 4 MHz 2. 4 to 8 MHz 3. 8 to 16 MHz
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- Julian It's good here |
6th Aug 2020, 7:30 pm | #8 |
Nonode
Join Date: Mar 2008
Location: Virginia Water, Surrey, UK.
Posts: 2,877
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Re: R210 Larkspur receiver
Good restoration! I got given one of these in exchange for a scope repair job a few years back. But why take out the vibrator? Mine works beautifully on vibrator with a friendly hum on 28V in. And it’s a much easier psu, as the set needs HT, LT and a -40V bias supply.
I assume you have all the circuits and connector pinouts. If not, give me a shout and I’ll drop some over at some point, or email. -Jeremy
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6th Aug 2020, 8:09 pm | #9 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,998
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Re: R210 Larkspur receiver
A nice fix.
I had one of them with a 'stripped' filmstrip-dial a while back: my solution was to fit a £10 chinese six-digit frequency-counter module (conveniently available with IF-subtraction by a set of DIP-switches) behind the glass window. They're not bad receivers, if you can forgive the not-SSB-friendly 'fast' tuning-rate and the 15MHz-broadcast-band images when tuning 14MHz. |
7th Aug 2020, 10:13 am | #10 |
Hexode
Join Date: Jul 2009
Location: Wokingham, Berkshire, UK.
Posts: 437
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Re: R210 Larkspur receiver
Hi all,
Not a great lover of electromechanical devices like vibrators, they were always troublesome in car radios, but I see the REME workshops do a FET variation on a theme so might try one of the, and as Jeremy says, easier power supply. I may strip everything off the front panel and respray it, it would certainly look better and as it is the cast metal character version no engraving filling in to do John Last edited by John Caswell; 7th Aug 2020 at 10:16 am. Reason: Addn'l info |
7th Aug 2020, 9:12 pm | #11 |
Dekatron
Join Date: Jan 2006
Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex.
Posts: 5,817
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Re: R210 Larkspur receiver
I saw some in the window of the surplus shop [opposite the Old Fire Station] at Oxford in the nineteen nineties. It was Sunday, it was shut and I was on my way North. I rang them up from Lancashire to reserve one and that was hard work-"Oh right, they'll probably be over in our warehouse !" When I eventually got back to Oxford they hadn't done that but there were three 210's left. Two were ok but the third had knobs missing or something. It was a bit rough so I tried to negotiate an all-in price for the three. No chance, to my surprise! So I said "Ok I'll just take the two good ones then" [I think they were £29-99p each]. The chap seemed to have difficulty adding up the price of two and said how about both for £40? After all that, I wasn't complaining I'd seen the SW Mag R210 conversion articles but I also just ran them off the 28v option that Jeremy went for. It was all very interesting but l didn't think the set [while it was built and performed very well] warranted me doing the work [if I could that is]. I also was beginning to recognise that preserving originality might be a good thing. It was a different story with WW2 equipment in the sixties of course. I agree these sets are pretty rugged. They remind me of the story re a US Bendix RX run over a by a truck and into the mud of a scrap yard [In The Radiophile I think] Apparently they dug it out, hosed it down and it worked
Dave W Last edited by dave walsh; 7th Aug 2020 at 9:26 pm. |
28th Oct 2020, 3:15 am | #12 |
Hexode
Join Date: Mar 2009
Location: Minneapolis, Minnesota, USA.
Posts: 278
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Re: R210 Larkspur receiver
For details on the design of the R210 see: J.A. Knight, "HF Band Communication Journal", A.T.E. Journal, April 1958. The A.T.E Journal was the house journal of Automatic Telephone and Electric Co., which later merged with Plessey. I have seen the article, but do not recall if I have a copy. It was referenced by Pat Hawker, G3VA, in his wonderful article "Trends in H.F. Receiver Front-ends". R.S.G.B. Bulletin, September 1963, pp 161-167.
73 John |
28th Oct 2020, 7:26 pm | #13 | |
Octode
Join Date: Nov 2010
Location: Ross-on-Wye, Herefordshire, UK.
Posts: 1,652
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Re: R210 Larkspur receiver
Quote:
So the R210 was really not a stand-alone receiver, it was part of a larger system, the C11/R210, which was typically used in vehicles, such as Landrovers and light lorries (like the Austin K9) which had a separate 24V power system, namely separate batteries and a separate alternator run off the engine from the normal vehicle 12V electrical system. Here's a pic of the whole lot: The R210 probably represents the best of the military HF sets from the era when valves were really the only option and AM & CW were the key modes used. Of course RTTY/FSK was also available with an add-on adaptor. The C11 is also a very nice unit, beautifully made, and with hi-level anode and screen mod on AM. Both units were simple to operate, which of course for the military is a key requirement. Richard |
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28th Oct 2020, 7:29 pm | #14 |
Octode
Join Date: Nov 2010
Location: Ross-on-Wye, Herefordshire, UK.
Posts: 1,652
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Re: R210 Larkspur receiver
I should add to the above that there is a mains power unit provided for the C11/R210 system, so it was evidently used sometimes as a ground station. It was a replacement for the earlier (WWII era) Wireless Set No.52. Not sure it was really much smaller or much lighter though than that earlier brute of a set. The handles you can see in the pic I gave in my last post optimistically suggest you can just cart this lot about........in fact you would be foolish to attempt anything less than a 2-man lift (unless you are weight lifter!)
Richard |