Eddystone 659/670 cabin set advice Wanted - UK Vintage Radio Repair and Restoration Discussion Forum

cernem1alt · 23rd Feb 2018, 3:25 pm

After 35 years of regretting selling my previous 670 I have another. Of course it comes with issues so some advice on solving these is needed. My skills are limited but a few successful repairs of Bush 90A's I am not totally without a clue so here goes.

First inspection not played with

Mains plug and lead missing any thoughts on this? and lets get it safely done, then first power up advice

on/off tone knob missing not the end of the world got a none matching knob but would like an original or close as.

any thoughts and advice very welcome

Thank you

Mike M1ALT

cathoderay57 · 23rd Feb 2018, 6:27 pm

Hi Mike, not sure if the Eddy 670 classes as a domestic or military set but I don't suppose it matters too much. If you don't have service data already, you can download the manual from the Eddystone User Group, free, from here: http://eddystoneusergroup.org.uk/ser...one-receivers/ You may wish to contact the User Group as somebody there might be able to supply the missing knobs. This appears to be a "live" chassis model so it is vital that, when fitting a mains lead, the neutral wire goes to the internal metalwork chassis (which should already be isolated from the outer metal case - but it's worth checking the isolation using a multimeter). I would in any case replace C1, C2 and C3 with Class Y new replacements to ensure case and aerial connection isolation is as good as can be. When fitting a mains cable consider sacrificing originality by fitting an IEC connector to ensure the mains stays connected at the right polarity. Then you may wish to check continuity of the heater series chain with a multimeter to see whether there are any open circuit valve heaters, dial lamps or mains droppers. Next I would replace C60 (0.01uF) with a mains-rated Class X new capacitor. Then disconnect the metal rectifier at the DC end from the electrolytic smoothing capacitor C58, the choke and the HT line. Check the metal rectifier with a multimeter for continuity in both directions. If it conducts both ways do not apply power! If it appears to conduct only one way then apply mains power with a DC meter across the disconnected end and check its off-load DC output. At this point you should be able to verify that the valves all light up. That's a starter for 10... Cheers, Jerry

G6Tanuki · 23rd Feb 2018, 7:01 pm

They can be good little bedside-radios if late-night broadcast-band SWLing and MW-DXing is your thing.

[Caroline's back on-air now on 648KHz!]

Expect to need to replace a bunch of coupling/decoupling capacitors 'the usual suspects' - just as you'd do with any other 60+ year old broadcast-band radio.

Some of the resistors - the ones with a white ceramic barrel and terra-cotta-coloured cement plugging the ends - made by Erie? - will have gone high too; generally the higher-value ones are the most drifty [check the screen-grid feeds and the anode-load resistor in the first audio stage].

The mains-dropper resistor may also 'smoke' when you first apply power. It's not smoke, it's steam! The ceramic former absorbs moisture from the air and this will boil-off if you power-up a radio that's been unused for some time.
And remember it's a live-chassis job!

cernem1alt · 23rd Feb 2018, 11:29 pm

Thank you all that is a great help.

turretslug · 24th Feb 2018, 1:34 am

The exposed-metalwork-but-mains-connected-chassis nature of these sets does mean that you need to be particularly careful that previous less-than-capable repairers haven't compromised safety by incorrect re-assembly- in the case of my 670A, not only had the volume pot's metal washer/nylon bush stack been replaced in the wrong order but the insulating washers and tube on one of the four front-panel-to-chassis screws had been mislaid and replaced by steel components.... Thus, one side of the incoming mains and the casework were effectively and reliably connected in not one but two places and I'm glad I'd checked thoroughly before powering!

TBH, if you've coped with sets like the ones you mentioned from the Bush stable, then there's not a great deal more to the Eddy, apart from the RF stage and a bit more bandswitching. It might be one of the less exalted of the range, but they're still sturdily and neatly made sets with clear scales and smooth, precise tuning. Good luck with it.

23rd Feb 2018, 3:25 pm	#1
cernem1alt Tetrode Join Date: Sep 2017 Location: Dorchester, Dorset, UK. Posts: 81	Eddystone 659/670 cabin set advice Wanted After 35 years of regretting selling my previous 670 I have another. Of course it comes with issues so some advice on solving these is needed. My skills are limited but a few successful repairs of Bush 90A's I am not totally without a clue so here goes. First inspection not played with Mains plug and lead missing any thoughts on this? and lets get it safely done, then first power up advice on/off tone knob missing not the end of the world got a none matching knob but would like an original or close as. any thoughts and advice very welcome Thank you Mike M1ALT

23rd Feb 2018, 6:27 pm	#2
cathoderay57 Nonode Join Date: Oct 2017 Location: Bristol, UK. Posts: 2,384	Re: Eddystone 659/670 cabin set advice Wanted Hi Mike, not sure if the Eddy 670 classes as a domestic or military set but I don't suppose it matters too much. If you don't have service data already, you can download the manual from the Eddystone User Group, free, from here: http://eddystoneusergroup.org.uk/ser...one-receivers/ You may wish to contact the User Group as somebody there might be able to supply the missing knobs. This appears to be a "live" chassis model so it is vital that, when fitting a mains lead, the neutral wire goes to the internal metalwork chassis (which should already be isolated from the outer metal case - but it's worth checking the isolation using a multimeter). I would in any case replace C1, C2 and C3 with Class Y new replacements to ensure case and aerial connection isolation is as good as can be. When fitting a mains cable consider sacrificing originality by fitting an IEC connector to ensure the mains stays connected at the right polarity. Then you may wish to check continuity of the heater series chain with a multimeter to see whether there are any open circuit valve heaters, dial lamps or mains droppers. Next I would replace C60 (0.01uF) with a mains-rated Class X new capacitor. Then disconnect the metal rectifier at the DC end from the electrolytic smoothing capacitor C58, the choke and the HT line. Check the metal rectifier with a multimeter for continuity in both directions. If it conducts both ways do not apply power! If it appears to conduct only one way then apply mains power with a DC meter across the disconnected end and check its off-load DC output. At this point you should be able to verify that the valves all light up. That's a starter for 10... Cheers, Jerry Last edited by cathoderay57; 23rd Feb 2018 at 6:32 pm.

23rd Feb 2018, 7:01 pm	#3
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,998	Re: Eddystone 659/670 cabin set advice Wanted They can be good little bedside-radios if late-night broadcast-band SWLing and MW-DXing is your thing. [Caroline's back on-air now on 648KHz!] Expect to need to replace a bunch of coupling/decoupling capacitors 'the usual suspects' - just as you'd do with any other 60+ year old broadcast-band radio. Some of the resistors - the ones with a white ceramic barrel and terra-cotta-coloured cement plugging the ends - made by Erie? - will have gone high too; generally the higher-value ones are the most drifty [check the screen-grid feeds and the anode-load resistor in the first audio stage]. The mains-dropper resistor may also 'smoke' when you first apply power. It's not smoke, it's steam! The ceramic former absorbs moisture from the air and this will boil-off if you power-up a radio that's been unused for some time. And remember it's a live-chassis job!

23rd Feb 2018, 11:29 pm	#4
cernem1alt Tetrode Join Date: Sep 2017 Location: Dorchester, Dorset, UK. Posts: 81	Re: Eddystone 659/670 cabin set advice Wanted Thank you all that is a great help.

24th Feb 2018, 1:34 am	#5
turretslug Dekatron Join Date: Nov 2011 Location: Surrey, UK. Posts: 4,395	Re: Eddystone 659/670 cabin set advice Wanted The exposed-metalwork-but-mains-connected-chassis nature of these sets does mean that you need to be particularly careful that previous less-than-capable repairers haven't compromised safety by incorrect re-assembly- in the case of my 670A, not only had the volume pot's metal washer/nylon bush stack been replaced in the wrong order but the insulating washers and tube on one of the four front-panel-to-chassis screws had been mislaid and replaced by steel components.... Thus, one side of the incoming mains and the casework were effectively and reliably connected in not one but two places and I'm glad I'd checked thoroughly before powering! TBH, if you've coped with sets like the ones you mentioned from the Bush stable, then there's not a great deal more to the Eddy, apart from the RF stage and a bit more bandswitching. It might be one of the less exalted of the range, but they're still sturdily and neatly made sets with clear scales and smooth, precise tuning. Good luck with it.