Hello,
I’m sure everyone will be quite excited to see my latest acquisition – a 60 year old Codar CR-70A receiver .. (pictured below)
When it arrived in it’s box, I was pleased to see it was in very good condition. With the cover off, it was clean with only light covering of dust. Easily brushed off with a paintbrush.
It has a shiny aluminium chassis with no sign of any modifications.
The mains plug and lead needed a bit of attention. The fuse rating was changed from 13 A to 3 A, and the connections (a bit loose and ragged) were re-fitted.
About a foot of green earth lead was removed from underneath the chassis. It had been wired from the mains entry point, all the way across the radio to the aerial / earth connectors. I used an empty hole in the chassis to fit a 3 mm earthing bolt with solder tag, and reconnected the earth lead to it – much neater.
The valves were carefully wiped, so as not to disturb the valve lettering. They appeared to be original GDR manufacture. The pin alignment was checked with my B9A setting tool.
All seemed to be in good order – no sign of over-heating anywhere.
The original knobs were removed along with the front panel. A bit of a careful cleaning, and everything replaced – except the main tuning knob as you can see, is now an Eddystone knob – sturdy and nice to handle.
The other knobs were replaced by FT101 knobs which are larger and easier to handle.
The mode selection knob is now a pointer style – looks better I think.
With everything replaced, the tuning was checked to move smoothly across the scale. I took the opportunity to diagram the tuning stringing pattern – just in case the string snaps. There's no detail of how to restring the tuning in any user guide I’ve been able to find.
Aerial connected, speaker connected. Time to switch on … phew – lights – music. Everything actually works.
Feed in test signals from my signal generator at various frequencies on each band. All near enough spot on.
Set tuning to low end of 14 Mc/s band – mode switch to CW / SSB – presto, nice Morse code signals.
I don’t think it gets much better than that. Absolutely on tune after all these years.
OK, the construction and components are not top quality, but they are still working.
I know opinion some years back on this Forum was less than enthusiastic, but I think to get such a fun to use and nice sounding radio from just 4 valves is quite an achievement.
The company Codar Radio seems to have disappeared without trace, and with no applause. So I’d like to give them a round of applause for innovative design and performance. Just look at the dual rate tuning, and the simple coil pack design.
Imagine how a simple 4 valve superhet receiver, built to modern standards would sound – I would suggest the analogue sound from a good speaker would be quite seductive. A good basis for a project I think ..
Anyway, I love it ..
Best wishes,
Graham G4EVW
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