Radio Rental Model 58

[Station X]

Drilling out rivets has never struck me as being particularly difficult. If access is difficult I use an Archimedean Drill or a pin chuck turned by hand.

On the other hand there's probably no justification for restuffing capacitors. It's a matter of personal choice. I restuff electrolytics, but I'm perfectly happy to replace waxies with yellow polypropylene types. Where's the sense in that?

They are rather nice looking cardboard cased caps though.

[John G8MWF]

The cardboard caps are staying - they look too good! Drilling out the rivet is not an issue 'if' I re-stuff them, but if re-stuffing them spoils their appearance then I would rather leave them alone and have obvious modern replacements tacked elsewhere.

I managed to get some modern yellow caps a the Tonbridge audio jumble from the BVWS stand and it was probably the most money that I spent on a single type of component.

The plan is to replace some critical components this evening and get HT on the other sections to evaluate what is going on and then do a full cap replacement.

[John G8MWF]

The plan went as expected and as needless to say all of the electrolytic caps need replacing.
Reception is only available on LW at the moment and more fault finding is needed.

The main problem are the valve bases.
These are pretty green. V3 is especially bad. So much so that it took quite a bit of cleaning just to get the heaters running and I fear that they will need replacing.

[John G8MWF]

Now that the holidays are over I have had a chance to look at this project again.

There appears to be a couple of sources for replacement OCTAL VINTAGE PAXOLINE VALVE TUBE BASE that look identical to those fitted.

Would it be a better idea to replace them with a different type of material and, if so, are there any direct replacements with the same mechanical fittings?

I looked at those in the RS catalogue and the modern Octal base replacements appear to have metric dimensions and I am not sure which, if any, vintage replacement would be the same size and fit.

This is simply an attempt to try and keep the look of the machine close to original and at the same time keep a good electrical functionality to it.

[Station X]

I have used "paxoline" valve holders like that and they have been fine.

If you search on something like "Octal Tube Valve Base Socket Holder" you may be able to find something better from somewhere like Langrex.

[Herald1360]

Don't forget that octal "relay" sockets are the same as octal "valve" sockets and may offer different availability. Beware of the contradiction in terms, the "11 pin octal socket" though!

[barrymagrec]

Standard (IO) octal bases from RS:- https://uk.rs-online.com/web/p/therm...bases/6784098/

[John G8MWF]

I looked at those but the hole sizes are different. The o/s diameter is 26.5mm and those in the chassis are a tad smaller so that would mean some filing and drilling which I would like to avoid if possible.

The idea of using NOS Paxolin holders is "OK" but they don't seem to be as well made as others that I have seen.
They also seem to be fairly tarnished before they are used and I wonder how long it would possibly be for new problems to show up?

[Ed_Dinning]

Hi John, chassis hole size is not normally an issue with these sockets as the valve is a standard size. The fixing hole centre are however.

Ed

[John G8MWF]

Hello Ed, I agree with you.
As a newbie I still haven't got that many spare valve sockets, none in fact, in my tool box.

Plan B is to go to one of the upcoming events and hopefully get hold of some for comparison.

I was hoping that I could get "official" dimensions for the Paxolin sockets to compare them but I haven't found it yet. The measurements I have made are no use unless I have details on the item I may want to replace it with.

Apart from new items, from modern suppliers, I cannot get any reliable information so hopefully I can go to a show with my rough measurement and try and match it up.

You may also have worked out that I am not a great fan of the Paxolin bases after seeing how flimsy they are and there tendency to corrode.

[Herald1360]

Hmmmm, couple of posts about IO and MO bases seem to have gone AWOL.

[Silicon]

I have measured the important dimensions of the rectifier valve socket on my Radio Rental 58 chassis.

The socket mounting holes are 38mm centre to centre.

The hole in the chassis is 34mm in diameter.

I noticed that an ebay seller in Hong Kong is selling Belton branded bakelite valve sockets which should fit.

A bakelite Octal socket on my valve tester (possibly Clix) has 38mm mounting hole spacing.

The 38mm mounting hole spacing is used on some other types of sockets i.e. Loctal.

[ColinB]

Post in the for sale and wanted section here, I'm sure these won't be too difficult to track down.

[Boater Sam]

Seen some on ebay, condition unknown.