VK5FRLH > 13-08-2017, 10:15 PM
VK4ADC > 14-08-2017, 08:05 AM
VK5FRLH > 14-08-2017, 09:51 AM
(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
VK5TM > 14-08-2017, 10:44 AM
VK2CSW > 14-08-2017, 05:36 PM
VK2ZIW > 14-08-2017, 06:42 PM
VK5FRLH > 15-08-2017, 10:10 PM
VK3ALB > 16-08-2017, 08:45 AM
VK5FRLH > 16-08-2017, 11:06 AM
(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.
VK3ALB > 16-08-2017, 12:15 PM
VK4WDM > 16-08-2017, 12:29 PM
(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
VK5FRLH > 16-08-2017, 07:24 PM
(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.
VK5TM > 17-08-2017, 02:55 PM