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Old 13th Jun 2019, 11:34 am   #1
ViperSan
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Default My Lovely old CR100

Sadly not much to listen to with it these days... but I've had it since I was 14 years old and am now 61.
About 2 years ago it was fully recapped and restored and is aligned and fully functional. That said I thought I'd showcase it.

Back when I was about 15 or 16 years old I studied for my RAE and passed.
But whilst studying I was overkeen and was building transmitters for the marine band close to MW, and yes I got caught, lol
I'll never forget my dads words when a rep from the GPO and a police man burst into my bedroom.
Needless to say I was taken by surprise and dad said "Well son, your first encounter with democracy and the system".
Luckily my CR100 was returned to me after being used in evidence but much of my gear was confiscated. I did have and R209 as well which I never saw again.

I passed my RAE but never applied for a call sign and after the encounter with the law lost interest.

Anyway, enough of my history as my main hobbies these days are restoring old computers from the 70s 80s and 90s and, less so these days due to having MS and a mother to look after who has dementia, satellite DXing C band KU KA etc.
regards
VS
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Old 13th Jun 2019, 2:29 pm   #2
turretslug
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Default Re: My Lovely old CR100

I think that they are under-appreciated, certainly as a wide-ranging SWL set, if not quite up to full amateur SSB expectations. There aren't many commonly-available sets with such comprehensive coverage- one would need both flavours of AR88, for example! Same goes for the usual Eddystones re. band-span. 2 RF stages and 3 IF amps make it a radio with intent and I always liked the smooth dual-speed co-axial tuning drive. They do have a bit of a name for drifting but as a broadcast receiver that's not as critical and after a few hours the worst of the wandering is over.

The first valve radio I ever re-built was a CR100- in retrospect, a bit of a dive into the deep end, but it worked immediately (OK, after about 20 seconds warm-up...) on power-up and gave many hours of entertainment, pulling in everything from MSF on 60kHz to 11m broadcasters with ease. One of my rountuit ideas is to re-build one using the loktal range valves- CR100s are sufficiently plentiful and un-appreciated that I don't think that this would be sacrilegious, this valve series was at least contemporaneous.
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Old 13th Jun 2019, 2:55 pm   #3
ViperSan
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Default Re: My Lovely old CR100

Yes indeed Turretslug drifting always was a bit of an issue but, once it had been switched on a while, acceptable.
When you think about its age it's still a functional piece of equipment and you can't say that about much these days.
Built like a tank and built to last.
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Old 13th Jun 2019, 6:50 pm   #4
G6Tanuki
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Default Re: My Lovely old CR100

Nice!

I have fond memories of a CR100 from the late-70s - when I "Hot-rodded" it by replacing the RF/FC/LO valves with modern ones [6AK5 as the first RF, EF85 as the second, ECH81 frequency-changer and 12AT7 LO] to get the front-end noise down - back then we had lots of sunspots and so listening to US CBers and Hams in the 27-30MHz range was all the rage.

I fitted a low-power 12V bulb in the oscillator-section of the coilbox and left this powered continually from a separate supply so the LO circuitry was always warm and ready-to-go without drift.

Alas - I didn't know then about the horrors of 'that capacitor' and the excessive HT-consumption led to the meltdown of the mains-transformer.
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Old 13th Jun 2019, 7:28 pm   #5
G4YVM David
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Default Re: My Lovely old CR100

That's a lovely looking radio.
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Old 15th Jun 2019, 2:22 pm   #6
AndyWright
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Default Re: My Lovely old CR100

I'm running a CR100 here with all original capacitors. Which one is "that capacitor". Does it connect to the grid of the audio output valve as in most other sets?

Cheers

Andy G4OJY
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Old 15th Jun 2019, 3:17 pm   #7
turretslug
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Default Re: My Lovely old CR100

That's the fella! When I rebuilt mine, I used a 10nF 630V polyester as they were in hand- very cheap insurance. Though I think G6Tanuki might be being a bit hard on himself- I gather CR100s always had a bit of a name for mains transformer meltdowns, mine did a few years after rebuild with a welter of waxy smoke and attention-getting whoosh (primary turns short?). They seem to be an unexceptional commercial quality item, rather than anything marinised or military spec. Happily, a junked and rather ordinary Sansui amp yielded a decent-quality mains transformer that was a mechanical drop-in and electrically excellent substitute.
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Old 15th Jun 2019, 10:59 pm   #8
Top Cap
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Default Re: My Lovely old CR100

I repaired one many moons ago, transformer was burnt out and all the screening covers were missing. I decided to gut it (done this many times before) and rebuild with B9A valves with screening skirts/covers. The worst capacitors to change are the big 0.1uF waxes that live in the RF compartments.
The pictures tell the story
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Old 16th Jun 2019, 1:11 am   #9
dave walsh
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Default Re: My Lovely old CR100

Very impressive TC!

Dave W
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Old 16th Jun 2019, 10:07 am   #10
barrymagrec
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Default Re: My Lovely old CR100

They used CR100s for our faultfinding training when I was an apprentice. Being basically lazy I just worked out the rough area of the fault and pulled out a couple of valves to find out which one they had cut a pin off.
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Old 16th Jun 2019, 3:27 pm   #11
Skywave
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Arrow Re: My Lovely old CR100

Quote:
Originally Posted by dave walsh View Post
Very impressive TC!
Indeed: truly a labour of love.

Al.
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Old 16th Jun 2019, 4:01 pm   #12
M0FYA Andy
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Default Re: My Lovely old CR100

Quote:
Originally Posted by barrymagrec View Post
to find out which one they had cut a pin off.
So they used really realistic faults to train people!!!

Andy
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Old 16th Jun 2019, 7:19 pm   #13
ms660
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Default Re: My Lovely old CR100

Snipping a valve pin was also a trick in some R&TV trade tests at interview time. I passed all mine.

Anyways back on subject....C96, if it turns into a low value resistance the output transformer could get stressed.

Lawrence.

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Old 17th Jun 2019, 11:36 am   #14
ViperSan
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Default Re: My Lovely old CR100

Looks like I'm not the only to appreciate these lovely old WW2 radios ..
No conversions on mine ..
Still running the original octal base valves..or for you US guys "tubes".
As you can see it has been modded at some point in its history ..
There is a knob missing ..and a signal strength meter has been added.
not by me though.
rgds
VS
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