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+--- Thread: Garage find - need info (/thread-298.html)
Garage find - need info - VK5FRLH - 13-08-2017
I happened to come across this unit but I have absolutely no idea what it is
I am assuming that it may be an old school of the air radio,
but as I say.... I have absolutely no idea
All I know is it was manufactured in Brisbane, and that it is an old valve and crystal unit
I have no idea of age or even how to hook it up
I am assuming it uses a straight wire antenna from the lug on the top right
I am not sure what the two positive and one negative posts are for
I am hoping someone out there maybe familiar with this unit and may be able to offer instructions on its use
The make and model is....
CRAMMOND CTR20 (Crammond Radio MFG. CO PTY LTD. Brisbane
Regards
VK5FRLH
RE: Garage find - need info - VK4ADC - 14-08-2017
The CTR20 model is many years old and (from memory) was used for RFDS comms.
"I am assuming it uses a straight wire antenna from the lug on the top right
I am not sure what the two positive and one negative posts are for"
Battery powered ?
You may find assistance from someone involved with the Historical Radio Society of Australia via their web site http://www.hrsa.asn.au
RE: Garage find - need info - VK5FRLH - 14-08-2017
(14-08-2017, 08:05 AM)VK4ADC Wrote: The CTR20 model is many years old and (from memory) was used for RFDS comms.
"I am assuming it uses a straight wire antenna from the lug on the top right
I am not sure what the two positive and one negative posts are for"
Battery powered ?
You may find assistance from someone involved with the Historical Radio Society of Australia via their web site http://www.hrsa.asn.au
Thanks VK4ADC for the response...
I hadnt considered the RFDS.... but that would probably make more sense
I would love to get hold of as much info on the operation of it as I can, so the Historical Radio Society may be the go....
I saw it, I knew it was old... and thought I want that... working or not just for the antiquity aspect alone lol
but it would be nice to fire it up and see it in action all the same
RE: Garage find - need info - VK5TM - 14-08-2017
While the CTR20 isn't listed on http://www.radiomuseum.org, there is a CTR24 which is described as a Marine Band transceiver for small craft.
The Tx frequencies listed for it match two of the frequencies in your photo, so your find was possibly also Marine Band.
Also, a couple of pictures here, about halfway down the page with a little bit of info.
http://www.radschool.org.au/magazines/Vol57/Page15.htm
Terry VK5TM
RE: Garage find - need info - VK2CSW - 14-08-2017
Let me start by saying I work in defence.
Having read this thread, I was looking for an official part no. at work. I was using a defence department online tool, when one of my searches threw out a line item that had the company name Crammond Radio Manufacturing Co Pty Ltd.
Now this could be a legacy item in the system but they appear to have a Commercial and Government Entity Code, or CAGE Code. It stems from the US Military ordering system but has spread to other parts of the world, mostly via NATO.
Now having a code probably indicates they still exist is some form, or did until relatively recently. The CAGE Code is Z0982. Australian entities usually have Zulu as the leading character.
I hope this helps your search.
(If I get a moment at work I'll see if there are any contact details for the company)
RE: Garage find - need info - VK2ZIW - 14-08-2017
I worked for John VK5MG in 1976 and installed Crammond's next generation, 4x 6CM5 valves
in the final. Transistorised 100W SSB marine set. 24V DC power, DC/DC with 4x 2N3055 transistors.
These frequencies are definitely Marine.
Yours is very likely an AM. The transition to SSB for Marine took place in about 1972.
2112, 2182, 2201, 2524, 4125, 4136.3, 6125, 6204 all Marine Coastal service and fishing frequencies.
The Crammond was considerably cheaper than the Racal, fully solid state in 1974.
RE: Garage find - need info - VK5FRLH - 15-08-2017
A big thanks to VK5TM, VK2CSW &VK2ZIW for all the info....
it is all extremely interesting BUT way over my head I am afraid....
I am not sure what use it is to me other than a eye-catching display piece for my radio room once its set up in the new place.
VK5TM - the hyperlink you attached was very interesting, and yes about halfway down in the radio section there is a radio that looks pretty much identical....
So at this stage the general consensus is that it is probably marine band radio and possibly used by the (US or NATO) defense forces stationed here during the second world war.... would this be accurate ?
RE: Garage find - need info - VK3ALB - 16-08-2017
Whilst Crammond (and many other manufacturers) would have contracted to the defense forces I think it would be unlikely this type of radio would have been regular issue. This style of radio, was made by many manufacturers and used not just for marine but anywhere phone lines did not reach.
There is still a fair bit of AM activity on the 40m, 80m and 160m bands. I imagine there would be a handful of hams in your area that would be interested in playing with that kind of gear.
It could have a vibrator style power supply in it which would allow it to be run from either 12 or 24 volts DC. Typical of the era the manufacturer would have recommended an end fed type antenna and there would have been a table in the back of the manual explaining to non technical type how the antenna should be built. There would also be notes explaining how to adapt the tank coil and perhaps additional filtering. Replacing the crystals with a AD9850 type VFO/Oscillator would be a simple way to get this gear onto the ham bands.
The resale value would not be very high. I think you'd be doing really well indeed if you could extract $100 out of someone for the set.
RE: Garage find - need info - VK5FRLH - 16-08-2017
(16-08-2017, 08:45 AM)VK3ALB Wrote: Whilst Crammond (and many other manufacturers) would have contracted to the defense forces I think it would be unlikely this type of radio would have been regular issue. This style of radio, was made by many manufacturers and used not just for marine but anywhere phone lines did not reach.
There is still a fair bit of AM activity on the 40m, 80m and 160m bands. I imagine there would be a handful of hams in your area that would be interested in playing with that kind of gear.
It could have a vibrator style power supply in it which would allow it to be run from either 12 or 24 volts DC. Typical of the era the manufacturer would have recommended an end fed type antenna and there would have been a table in the back of the manual explaining to non technical type how the antenna should be built. There would also be notes explaining how to adapt the tank coil and perhaps additional filtering. Replacing the crystals with a AD9850 type VFO/Oscillator would be a simple way to get this gear onto the ham bands.
The resale value would not be very high. I think you'd be doing really well indeed if you could extract $100 out of someone for the set.
Thanks for the info....
I would dearly love to get hold of an original/copy user manual for it.
I am actually more curious about it as I know it is old and therefore to me something of interest/curiosity and worth holding onto as a keepsake.
I wasnt trying to get it appraised or anything.... just wanted to know what it is that I have.
In-fact I only paid $50 for it and it seems to work.... just having it sitting on my bench really gives a feel of antiquity and contrast amongst my other radios.... kind of a now and then feel..... humble beginnings lol
I was toying with the idea of giving it a fresh coat of paint matching the original color etc.... but decided that would only detract from the historical significance.
RE: Garage find - need info - VK3ALB - 16-08-2017
Understood Bob,
I'm a HRSA member and have posted a request on a mailing list frequented by folks who restore old radios. If anything comes of it I'll let you know.
I imagine the historical significance would be high for only a very small number of people. The front panel color is not unusual and a company called Weston also used it for a similar style of radio. It reminds me of old weatherboards and must have been a bargain price back in the day. :-) Looks like that panel would need a lot of prep to make the new paint stick.
RE: Garage find - need info - VK4WDM - 16-08-2017
(13-08-2017, 10:15 PM)VK5FRLH Wrote: I happened to come across this unit but I have absolutely no idea what it is
I am assuming that it may be an old school of the air radio,
but as I say.... I have absolutely no idea
All I know is it was manufactured in Brisbane, and that it is an old valve and crystal unit
I have no idea of age or even how to hook it up
I am assuming it uses a straight wire antenna from the lug on the top right
I am not sure what the two positive and one negative posts are for
I am hoping someone out there maybe familiar with this unit and may be able to offer instructions on its use
The make and model is....
CRAMMOND CTR20 (Crammond Radio MFG. CO PTY LTD. Brisbane
Regards
VK5FRLH
Crammond radios were in common use during the 1940's, 1950's and 1960's for a variety of civilian uses (the one in question has marine frequencies written on it) and there may be a variety of museums etc that would interested in it but they would probably want it donated rather than pay for it.
I would not worry about a paint job but please give it a really good careful, gentle, clean with a blower or vacuum cleaner. Have a good look to make sure that there are no leaking oil-filled capacitors or transformers because they might contain Polychlorinated Biphenyls (PCB's).
Wayne VK4WDM
RE: Garage find - need info - VK5FRLH - 16-08-2017
(16-08-2017, 12:15 PM)VK3ALB Wrote: Understood Bob,
I'm a HRSA member and have posted a request on a mailing list frequented by folks who restore old radios. If anything comes of it I'll let you know.
I imagine the historical significance would be high for only a very small number of people. The front panel color is not unusual and a company called Weston also used it for a similar style of radio. It reminds me of old weatherboards and must have been a bargain price back in the day. :-) Looks like that panel would need a lot of prep to make the new paint stick.
Thank you, much appreciated...
as suggested earlier by VK5TM..... I looked at the site http://www.radschool.org.au/magazines/Vol57/Page15.htm
I left a message with them about the radio but as yet have not heard from them...
I still may take out the drawers and give it all a gentle blow out with the compressor and possibly restore the face and box....
I will see how it goes...
Bob
RE: Garage find - need info - VK5TM - 17-08-2017
This is just a guess, but I would put the age of the radio around mid/late 50's very early 60's based on the date of 1964 for the CTR24.
Terry VK5TM