Before I Drive Myself Nuts!!

[Bushbaby]

Hi Joe,
Checked - I replaced the one in there very recently with a Welwyn cap which measured 30R before i put it in.

Regards

Rob

[Joe]

There's not much else it can be as that's the only thing between the neutral side of the switch and the chassis. Darned odd.

- Joe

[Bushbaby]

Have I still wired the switch correctly?? Its the only bit of the radio that I am unhappy about. Its an alpha 470kR pot and its not clear at all what the terminals are they are just marked if I recall correctly A, C, F & H.

Otherwise, I'm stumped. Will a knackered thermister make a difference??

Thanks

Rob

[pwdrive]

Hi Rob, if the problem is on the neutral side then according to the manual the thermistor will not make any difference, maybe time to check that switch again, refer to the diagram that David posted, the switch you have should be a DPST (double pole single throw) one pole and its ascociated contact is isolated from the other pole and it's ascociated contact ie two seperate switches actuated by one insulated mechanism, determine each set of contacts with your avo set to R and mark them or draw a simple plan view and mark the plan. You need to mark them as live in and live out on one set of contacts and neutral in and neutral out on the other set of contacts.

Lawrence.

[Steve_P]

On these sets, there should be 30 Ohms between Neutral and Chassis. Check it.

If you don't have any valves lighting up, it's more likely to be a valve heater or a bit of dirt on a pin. Clean them all and try again.

If the thermistor is O/C then you will not get any life from the valves. You can replace with a 47 Ohm resistor if needed, 10 Watts or thereabouts. Unlikely though.

As far as the switch goes, get your meter on the ohms range and you will find by testing pins that 2 of them conduct when it is on. The other two should as well. Then connect the mains lead to one end and the other ends to the set, Live mains to Live set, Neutral Mains to Neutral Set.

Cheers,

Steve P.

[tiv48]

rob could you post a picture of the mains switch? and maybe the under chassis.
rob t

[Bushbaby]

Hi All,
Thanks for your most valued help and I do apologise if it appears I'm drawing this one out - I don't mean to but I really would like to get this set working.

Regards

Rob

[Bushbaby]

Hi Rob
As requested.....I'm off to bed!

Regards

Rob
   

   

   

[Joe]

It looks like your switched neutral wire is green but the one going to R38 is orange.

I'll get the chassis out of mine tomorrow and try and get some photos for you to compare.

- Joe

[Joe]

I've found a picture from when I did mine and there seem to be quite a few differences on the tag-strip in the bottom right corner:-

   

Usual drill: Right-click and "Open in New Tab."

- Joe