Information for restorers

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 Tip No.1 Restoring Roberts radios

 Tip No.2 Restoring valve radios

 Tip No.3 Aligning radios

 Tip No.4 Restoring radio cabinets

 Tip No.5 Use of glue to secure components

 Tip No.6 Heater chains

  Tip No.7

It's important to not rely on simple test equipment to measure DC resistance or an ESR value when it comes to old condensers because once HT is applied their characteristics can change dramatically

WW2 Tubular condenser leakage

Large WW2 metal-cased condensers

 Tip No.8 Repair old condensers from new capacitors


 Stuffing old wax covered condensers


 Renewing metal can condensers


Tip No.9 Refit a top cap on an old valve

I'm sure you wouldn't pull the top cap off a valve, but the previous owner of an old radio might have done this. If you can solder it back on all well and good, but if the wire is broken off you can still sometimes fix it.


Tip No.10 Renew an old mains lead

When it comes to WW2 military radios I'd usually recommend not messing with mains leads and to replace such a thing with something that is, or at least looks as old as the radio, but domestic radios are a different matter. If you repair an old radio for a customer that's keen to put the thing back in service then the mains lead becomes important. Any rubber-covered mains lead from before say 1970 is either perished or soon will be. The older the lead the more likely the rubber insulation will be hardened and cracking.

One option is to fit a new plastic-insulated mains cable, but another solution may be better. Fit an IEC socket on the chassis. This neatly solves not only the problem of a new mains lead, but also how to bring an early chassis-mounted connector up-to-date. See picture below.

 Many radios use a two-pin chassis-mounted mains connector having a special design. Many allow the mains lead to be plugged in either way round and, of course having only two pins, have no safety earth. Let's pause at this point to consider AC/DC sets. These require careful consideration because of the problem of a live chassis and so fitting an IEC connector will not be as straightforward as is the case of an AC set. If in doubt do not proceed to modify an AC/DC set. If you do proceed then do so having carefully considered all aspects of electrical safety. If you don't know how to identify an AC only or an AC/DC set you should not even consider handling an old radio.

Having mentioned WW2 military radios I'll briefly discuss these and also those using valves that were made up to around 1970. You'll have surely noticed that modern mains plugs have an earth pin which is longer than those used for live and neutral. This is to ensure that any exposed metalwork is connected to the safety earth connection before live or neutral connections are made. If the earth pin isn't longer then the odds are that grasping a case and inserting the mains lead will be a painful experience. One option is to never unplug the lead.. another is to only plug it in before the 13 amp plug is inserted into the mains. A better option is to replace the offending plug/socket pair with an IEC plug/socket. One such radio might be a Murphy 62B Receiver which uses a Plessey style mains plug carrying three pins having the same length.


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