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Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
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11th Sep 2008, 9:18 pm | #1 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
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1930 Cossor Melody Maker.
I recently aquired 3 radio receivers and an Ekco model LS2 mains energised speaker in a Bakelight (aka Bakelite) cabinet. These items have been stored for the last 70 years in a 'time warp' commercial premises.
One of the sets is a Cossor Melody Maker from around 1930. It is in incredibly good condition with an unmarked cabinet and the original battery leads and wander/spade plugs. Curiosity got the better of me and this afternoon I decided to see if I could get a tune out of it! First I tested the intervalve transformer and to my delight found both primary and secondary windings intact. There are three H.T. wander plugs marked H.T. 1 H.T. 2 and H.T. screened grid. One marked H.T. negative, another L.T. positive and the last external lead marked L.T. negative. A clip inside the receiver originally housed the 9v grid bias battery and there were two further wander plugs for these! An ORMOND high impedence moving iron speaker was borrowed from the 'museum' and connected to the to connectors to the right of the cabinet. Next my home brew mains power supply was connected to the receiver by simply tacing the various H.T. connections. Around 60V was supplied to the screen of the R.F. tetrode type 215SG, 90v to H.T. 1 and 120v to H.T. 2, the output stage. 2V was set on the PSU regulator and supplied to the filament supply spade connectors. 4.5V grid bias was supplied via a 1289 battery. With power applied..Nothing! The 'pull on/push off' switch was slightly tarnished and a clean up produced a faint hum from the speaker and some odd crackles. Touching the grid of the output triode produced a very welcome faint hum proving that the stage was working to some degree. Repeating the test on the grid of the detector triode produced an even louder hum, even more exciting! [I must get out more] Still no signals with the workshop aerial applied. Measuring the filament voltage to the R.F. detector valve produced a zero reading and this was somewhat puzzling. Tracing the wiring showed that the filament supply to this valve was supplied via a front mounted reostat [volume/sensitivity control] that was set to maximum resistance. I cleaned the control and set it to minimum resistance and at last had 2V across the 215SG. Still no signals, loud hum on anode but nothing at control grid... With care I removed the valve from its mid way position in the screening partition and cleaned its pins with a fibre pencil. The screw connections to the valve holder were removed and cleaned and everything reinstalled. Upon switch on I was rewarded with the strains of Elgars Enigma variations transmitted by a French programme on Long wave and rocking the tuning capacitors and reaction control produced incredibly loud very good quality reproduction. To be honest I could hardly believe it! More connections were unscrewed, cleaned and tightened and the general dust was removed from the cabinet internals. The results are truly amazing. Many long wave and Medium wave stations [marked short on this pre Brookmans Park receiver] can be received with ease and I am simply amazed at the quality reproduced from that ORMOND speaker. The sets performance must have impressed its proud owner when first installed as it did for me this afternoon. It was a very pleasant excursion into the early days of radio and to hear what an early set actually sounded like. I have attached a few pictures showing the set as found and finally working with the vintage loudspeaker. The power unit 'lash up' can be seen on the right. Regards, John. |
11th Sep 2008, 9:54 pm | #2 |
Pentode
Join Date: Aug 2005
Location: Dublin, Ireland.
Posts: 157
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Re: 1930 Cossor Melody Maker.
i like your art deco speaker , maitiu
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11th Sep 2008, 9:58 pm | #3 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,194
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Re: 1930 Cossor Melody Maker.
Hi John, that may be the one of the earlier melody makers; there were several versions from about 1927 onwards, including mains sets.
Most of the 30's sets look like yours externally but have 2 coils in larger cans inside, with the W/C switch on the underside of the coils, operated by a sliding bar under the middle of the set. The SG valve was also chassis mounted, not through a screen and caps were nice brass jobs. Ed |
11th Sep 2008, 10:00 pm | #4 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,846
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Re: 1930 Cossor Melody Maker.
That's amazing, John!
I too rather like the styling of that speaker. Nick. |
11th Sep 2008, 10:24 pm | #5 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
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Re: 1930 Cossor Melody Maker.
Thanks for your comments. I have quite a few interesting speakers. I will put them on a thread when I have an hour to spare.
Thanks for the info Ed. The wavechange switches are nickel plated toggle switches on the top of the coil assemblies. J. |
13th Sep 2008, 3:52 pm | #6 |
Heptode
Join Date: Aug 2006
Location: Sheffield, South Yorkshire, UK
Posts: 990
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Re: 1930 Cossor Melody Maker.
Hello John
Usually these early sets are not my cup of tea, but in this case I must echo Nick's comment of "that's amazing!" I just wouldn't have thought the performance would have been anywhere near as good as that you have described. You've given me renewed interest in tackling a Wayfarer Major portable now from the mid 1930's that I've had on the 'to-do' pile for far too long! A first class job, very well done! Regards |
13th Sep 2008, 6:15 pm | #7 |
Dekatron
Join Date: Jul 2008
Location: Charmouth, Dorset, UK.
Posts: 3,601
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Re: 1930 Cossor Melody Maker.
My grand parents had a Cossor Melody Maker with a seperate speaker similar to yours but it was mains and had two tuning controls close together in the centre with escutchions showing numbered dials. I have never seen one since.
I can remember as a child, lying in bed upstairs and hearing the 7.00 am news through the floor. They only had one power point and that was a 2 pin 5a in the kitchen, there was a lead running around the picture rail into the dining room where the radio was, everything else plugged into the light! Peter.N. |
13th Sep 2008, 7:57 pm | #8 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
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Re: 1930 Cossor Melody Maker.
Hello Robert,
This set has a truly amazing performance and has rekindled my interest in vintage radio that has become somewhat cool recently. This even stimulated me to spend Saturday afternoon erecting a vintage aerial array strung between the house and the garage. I spent over two hours looking for a box of egg insulators 'put in a safe place' to no avail. I had to make some in the end from a block of solid pvc. [Phenolic?]The ORMOND speaker gives incredible audio quality [150mw!] far better than I had expected. The valve line up is 215SG screened tetrode H.F. amp. 210RC leaky grid detector and 215P output. All Cossor valves of course complete with the lozenge shaped labels. The selectivity is very good and stations can be easily separated with the twin tuning condensers. I have now cleaned the cabinet and consider the project complete! Thanks again for your interest. Regards, John. |
14th Sep 2008, 8:55 pm | #9 |
Nonode
Join Date: May 2006
Location: St Albans, Herts, UK.
Posts: 2,193
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Re: 1930 Cossor Melody Maker.
Hi John.
Now that IS vintage! Well done on a nice restoration (and write up!) Cheers, Tas |
15th Sep 2008, 7:55 pm | #10 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
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Re: 1930 Cossor Melody Maker.
Thanks Tas. I have just noticed the correction to my spelling of Bakelite. I have spelt that correctly for over 40 years......I'm ashamed..I will try to find something even earlier than the Cossor and see how it goes. Regards, John.
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15th Sep 2008, 10:52 pm | #11 |
Dekatron
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
Posts: 7,572
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Re: 1930 Cossor Melody Maker.
It's amazing to think that that radio has been idle for most of it's 70-odd year life and stored for so long and with minmal effort and work (and presumably no replacement parts) is now restored to full working order....and today I scrapped a 3 year old DAB radio.....say no more!!
Rich.
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There are lots of brilliant keyboard players and then there is Rick Wakeman..... |
16th Sep 2008, 8:18 am | #12 | |
Dekatron
Join Date: Nov 2003
Location: Near Leeds, West Yorkshire, UK
Posts: 4,609
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Re: 1930 Cossor Melody Maker.
Nice job indeed, John - you'd have been wondering where the timebases were at first, then?
Quote:
I think the "Melody Maker" tag was used a bit like Ultra "Bermuda" and applied to all sorts of models, including self-build plans. I had a 3-valve Cossor Melody Maker from the late 20s once, complete with the original building instructions.
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Mike. |
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16th Sep 2008, 8:44 am | #13 |
Rest in Peace
Join Date: Jul 2006
Location: Somerset, UK.
Posts: 2,356
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Re: 1930 Cossor Melody Maker.
Nice to see something early for a change . we have gone very "Modern" lately
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