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Author Topic: R1155 Beautiful!  (Read 11788 times)
KB1WSY
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Posts: 812




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« Reply #15 on: January 12, 2014, 06:33:56 AM »

Thus the saying that "Perfection is the enemy of good enough".

I think that was Voltaire ... lemme look it up. Yup, here it is:

Dans ses écrits, un sage Italien
Dit que le mieux est l'ennemi du bien.

(In his writings, a wise Italian
says that the best is the enemy of the good)

I have been trying to apply that saying to my Morse-code learning but so far not very successfully. I'm one of those cussed perfectionists ... guess I would have lost the war.

More wisdom via Wikipedia:

"Watson-Watt, who developed early warning radar in Britain to counter the rapid growth of the Luftwaffe, propounded a 'cult of the imperfect,' which he stated as 'Give them the third best to go on with; the second best comes too late, the best never comes.' "

73 de Martin, KB1WSY
« Last Edit: January 12, 2014, 06:36:04 AM by KB1WSY » Logged
G3RZP
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Posts: 4828




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« Reply #16 on: January 12, 2014, 02:37:09 PM »

While Watson-Watt took the credit for an awful lot of other people's work......he was just a manager, and like so many managers', took credit for the work of his juniors.
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KA4LFP
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Posts: 66




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« Reply #17 on: January 12, 2014, 09:30:02 PM »

and I've heard that one of the time saving ideas involved not painting much of the interior metalwork above the primer level (this story could be pure urban legend). On one hand it's incredibly shoddy to send an iron boat to sea without complete rust prevention, on the other when Liberty Ships had a life expectancy of less than a year during the peak of the war for the North Atlantic anything above primer was a waste of time and paint.

I believe that was true at a certain timeframe in the peak of things.
They shipped out with paint onboard (or allegedly onboard) with someones dim idea that the crews (and onboard soldiers) could finish the painting while at sea!
Granted that many a sailor chipped and painted a lot, but I don't know that hand painting the entire inside of a whole
ship including all inaccessible areas due to mounted equipment while fighting off U-boats was
something that could have been done!

As you said, not everything was done right just because immense efforts were underway and great sacrifices and massive manpower. Much went awry and the only saving grace was hundreds  of hands to put it somewhat right
but never get to what should have been done..
I've heard stories about SeaBees that way too -- guys who actually did the work talking about how if civilian contractors had done decent work, it would not have taken 50 extra guys to get half of it put together badly... yet that's not what idealized history would tell us...
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KB1WSY
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Posts: 812




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« Reply #18 on: January 13, 2014, 03:23:26 AM »

While Watson-Watt took the credit for an awful lot of other people's work......he was just a manager, and like so many managers', took credit for the work of his juniors.

Including I suppose my great-uncle Christopher Marris, who, according to family lore, was on the team at GEC that developed the cavity magnetron. Warning: I have no idea whether any of this is true, just passing on what I was told. I also expect that the magnetron will turn out to have been invented in several places at once, huh?

73 de Martin, KB1WSY
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GW3OQK
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Posts: 155




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« Reply #19 on: January 13, 2014, 04:45:22 AM »

YES Martin. Randall and Boot at Birminham University invented the resonant cavity magnetron and early in WW2 GEC made production models, so no doubt Uncle Christopher was there. Lots to read about it on the web and in books. Then I recall early models were brought to USA by Welshman Taffy Bowen to go into production there.

Strange how threads drift off the original subject. Anyway the R1155 has been sold, and 2 more have appeared on the auction site. Amazing how many are still around and working after 70 years so I consider it anything but a crap radio myself. I'll have my gear on next week end just to see if I can make any qsos in the antique wireless association contest.

73
Andrew
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G3RZP
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« Reply #20 on: January 14, 2014, 04:07:50 AM »

Martin, how right you are when you say "I also expect that the magnetron will turn out to have been invented in several places at once, huh?"

Randall and Boot were by no means the first to discover the cavity magnetron. Yesterday, the IEEE Antennas and Propagation Magazine Vol 55, no. 5, October 2013 arrived. P244 et seq has an article on the history of the cavity magnetron. As early as 1934, the cavity anode idea for magnetrons was around: patents were filed by Bell Labs (1934), Telefunken (1934, 1938), University of Leningrad (1937). Nakajima in Japan had an 8 cavity magnetron producing 500 watts CW at 10cms in April 1939.

Sir Bernard Lovell, with the benefit of hindsight wondered if all the secrecy regarding the magnetron was worthwhile, since when the Germans did capture an H2S, they immediately recognised the magnetron as working on the principles published by the Leningrad university workers in 1936!

One of the leading workers in the field was at the GEC Research Labs at Wembley: he was Dr. E. C. S. Megaw, G6MU - originally GI6MU before he moved to Wembley to work for GEC. (There has to be a radio amateur somewhere in all this!) After Randall and Boot produced their first 6 cavity continuously pumped water cooled CW prototype in February 1941, Megaw produced by May 16, 1941, a sealed six cavity model working in pulse mode, the E1188, with an electromagnet weighing less than 50 pounds. By May 25 an improved low height air cooled version, the E1189, was produced using a permanent magnet. It had a short life because of evaporation of the spiral thoriated tungsten filament. Pre-war collaboration between Megaw and the Frenchman, Ponte of CSF, had led to consideration of cathodes, and Megaw used an oxide coated cathode 0.45cm in diameter in the second E1189. On June 26, that tube was producing 15kW pulses with a reasonable life span. It was also Megaw who discovered the back heating effect of electron bombardment of the cathode. For the first time, a manufacturable and field useable design was available

So despite all the claims, Randall and Boot were by no means the first in using cavities in a magnetron. GEC were the first to make a suitable device for actual use outside the laboratory, but even so, it would not have been much good without the external cavity klystron for receiver local oscillators, developed by the team under Sutton at the University of Bristol - the same techniques were used for T/R cells, too - and the work at the BTH labs at Rugby to produce the silicon mixer diodes for the radar receiver.

 
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G4CMY
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Posts: 14




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« Reply #21 on: January 14, 2014, 05:32:41 AM »

This thread brings back many fond memories for me.

When I first got into amateur radio I was a schoolboy with no money. My Elmer was my Chemistry teacher who gave me an R1155N which I used firstly as an SWL for a couple of years then when I got my license in 1973 I carried on using it with an ex army 62 set as a transmitter for 160m, 80m and 40m.  If I remember correctly I modified the 1155 to have separate AF and RF gain controls and a BFO control knob both of which helped to improve the cw reception.

I also used a modified RF24 unit as an HF bands convertor (20m, 15m and 10m), a BC453 as a second IF and a home brewed op-amp audio filter for cw. It all worked remarkably well if you knew how to drive it.

I used that combination (along with a variety of home-made QRP rigs and an HW7) for many years until I progressed to my first commercial rig, a TS120V, which I have only recently retired in favour of an FT817nd and FT450D.

The R1155 might not have been very good technically but it enabled ne to hear stations from all over the world and got me well and truely hooked on radio. It is to me a thing of beauty Grin

Thanks for the memories

Tony G4CMY





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KB1WSY
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Posts: 812




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« Reply #22 on: January 14, 2014, 07:32:55 PM »

(1) Concerning the Magnetron, this is quite fascinating. I probably ought to track down the "uncle Christopher" clues before it becomes impossible due to the passage of time. That branch of the family is now relatively distant from mine but perhaps there are some people alive who could provide more information. (Nowadays, many of them live in the Birmingham area.)

(2) I will take this opportunity to repeat my mention of my Elmer, G3PNV, Geoffrey Andrews, whose call is still active and mailing address listed as Amersham, Bucks. I am writing to him ... but if anyone has knowledge of him or even just a QSO record from recent years.... Last time I saw him was in approximately 1973. He would now be in his 80s, I suppose.

(3) For G3RZP: I'm in the southern UK in the 3rd week of March, are you interested in a drink somewhere in the vicinity of your QTH, which I will be driving fairly close to on my way elsewhere? By then, I may even be On The Air and your online and emailed Elmering will have had something to do with it.

73 de Martin, KB1WSY


« Last Edit: January 14, 2014, 07:36:14 PM by KB1WSY » Logged
G3RZP
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Posts: 4828




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« Reply #23 on: January 15, 2014, 12:47:45 AM »

Martin,

March 11 and 25 at 1400 are (doubtless expensive!) appointments with the dentist. Mornings of March 6 and 20 are booked, otherwise all is clear. Telephone is 01 666 860423
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G4FUT
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Posts: 88




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« Reply #24 on: January 15, 2014, 01:26:49 AM »

Reference to mass produced wirelesses being rubbish.  I was a British Army wireless operator, 1956-60, and had on many oaccasions to use the WS19 on active service. Even at that date many came brand new encased in waxed wodden boxes with Russian writing, and we hated the thing. Many succumbed to "accidents" so they could be "BER"...Beyond Every Repair, and replaced with the WS62.
My experience with the R1155, (with which I fell in love) came when my father bought one for me in 1950.  It cost ¬£5.19.6p and its matching PSU was the same size and price. BTW, that sum was about one weeks wages then, the total being a mans wage for 2 weeks.
The R1155, epitomised what I always though a wireless set should look like. I didn't know about performance then, but even in the 1960s it would still bring in 9N1MM, Fr. Moran. I was a happy bunny! Grin
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Even if the voices aren't real, they have some pretty good ideas
KB1WSY
Member

Posts: 812




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« Reply #25 on: January 15, 2014, 02:45:01 AM »

Martin,

March 11 and 25 at 1400 are (doubtless expensive!) appointments with the dentist. Mornings of March 6 and 20 are booked, otherwise all is clear. Telephone is 01 666 860423

Thanks Peter. It would probably be Friday, March 21 or possibly Monday, March 24. Will be in touch closer to the date. Would be fun to meet you.
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GW3OQK
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Posts: 155




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« Reply #26 on: January 15, 2014, 05:41:18 AM »

FUT and CMY, I QSO MW0LUK most Sundays at 1945 - 2000 on 3.545 kc/s (+/-) He may well be using the WS62, and me on the T1154. You'd be welcome to call in.

I bought my R1155 in Manchester and carried it home on foot for about 2 miles. The PSU was made from parts from a scrap domestic radio. Later I bought a T1154 which at 46 lb I had to put down every 100 yards at first, reducing all the way home.

After I'd mentioned Randall & Boot I thought I'd better change it to "developed their version of ..." before ZRP came in with the full wazoo but left it to see how long it took. Well done Peter. I once had a book about R&B's development giving great lab-book detail such as measuring the freq at 9.8 cm with lecher lines etc. Wonder what it was. http://www.cap.ca/wyp/profiles/Redhead-Nov01.PDF is more general info.

About  "first inventions" I was reminded of Alexander Fleming's discovery of Penicillin which remained unusable for many years until Florey & Chain developed it to a useful product. (OK, some others had previously been experimenting.) A fellow once assured me that Michaelangelo invented the helicopter, but I dont think it flew very well

73
Andrew



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G3RZP
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Posts: 4828




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« Reply #27 on: January 15, 2014, 09:52:22 AM »

Andrew

Good job it wasn't an R107 or an AR88!

My father (G8ON) taught the T1131 VHF ground station TX and its associated R1132 Rx, as well as the R1155 and T1154 in his time at RAF Cranwell. His squadron leader was G6NZ. This may explain his somewhat jaundiced view of the R1155 compared with the BC348, and of the poor performance of the DET12 triode.
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GW3OQK
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Posts: 155




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« Reply #28 on: January 16, 2014, 11:20:26 AM »

Is this the worst R1155 hack you have ever seen?
http://www.ebay.co.uk/itm/WW2-Bomber-Radio-receiver-spares-or-repair-plus-radio-parts-/201020187381?pt=UK_Collectables_RadioTelevision_Telephony_SM&hash=item2ecdbca2f5

Andrew
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G3RZP
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« Reply #29 on: January 16, 2014, 11:58:04 AM »

Andrew,

I used Lecher lines back in the 1960s when experimenting with the 10cm H2S receive klystron.....Then in the early 1980's, using the coax version, the slotted line, to measure the input impedance of 2 GHz divider integrated circuits.

Sadly, these things aren't taught so when it is necessary to measure something like 150pF in series with 3 ohms at 400 MHz and the VNA is not accurate at those levels, people don't know how to do it.
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