PYE P76F Wave Change - UK Vintage Radio Repair and Restoration Discussion Forum

greencroft · 27th Jan 2022, 11:01 am

The wave changer dial indicator slips on its spindle very easily. It seems to be held on the spindle by the cord. Is this correct? When changing wavebands the dial slips and eventually indicates the wrong band. Should the plastic dial be held in place by any other means other than the cord?. Help appreciated. Thanks

greencroft · 27th Jan 2022, 4:39 pm

Quick update. When wave switch in short wave position there is zero tension on spring holding one end of drive cord. Spring tension increases as switch moved to G position. Anyone know what the correct tension should be?

Cobaltblue · 27th Jan 2022, 5:05 pm

From the manufactures service sheet available above.

https://www.service-data.com/product...11/6662/m15211

Cheers

Mike T

greencroft · 27th Jan 2022, 6:32 pm

Mike I have the service sheet which shows route of cord but nothing about correct tension. Also should it be silicon lubricated or wax. Or dry

PYE 405 · 27th Jan 2022, 6:52 pm

Hi, I don't think that there is a specific tension as such, but with mine I simply adjusted it so that the spring only just held the wire taught at the most relaxed position (SW). The indicator should of course be able to rotate freely on it's spindle, but I can't see any need to apply wax or silicone to the wire.

It is possible that the wire might have stretched slightly, so it may be a good idea to check the length according to the data rather than alter the actual spring.

PYE 405 · 27th Jan 2022, 7:23 pm

Just to add to the above, I do believe there is a small notch that the wire passes through on the plastic indicator shaft. This probably serves as a securing point, but if worn, perhaps a very small dab of glue may help to keep the indicator from slipping due to the action of abrupt switch rotation.

greencroft · 27th Jan 2022, 9:00 pm

Andrew, thanks for the info. My cord is not going through any notch on the plastic dial it's just wrapped around the dial

PYE 405 · 27th Jan 2022, 9:56 pm

If your set has a cord instead of wire, then perhaps it was replaced I wonder. It could have been fitted from new though, especially as there is no notch in the indicator shaft.
In that case, a waxed cord might offer better grip than one without.

greencroft · 27th Jan 2022, 11:26 pm

Andrew there is a notch just that the cord isn't going through it. It is now. Also it is cord not wire. Thanks for the info. Ken

greencroft · 9th Feb 2022, 10:18 am

Update re wavechange switch it appears the relaxed position is not Shortwave on my set BUT G. Bluetooth works through the Shortwave selection and Longwave is TB.!!

John10b · 9th Feb 2022, 1:32 pm

Take a look at your other post, which I answered.
John

greencroft · 11th Feb 2022, 10:11 am

Thanks for reply. Problem due to cord wound back to front.

27th Jan 2022, 11:01 am	#1
greencroft Triode Join Date: Jan 2022 Location: Hexham, Northumberland, UK. Posts: 24	PYE P76F Wave Change The wave changer dial indicator slips on its spindle very easily. It seems to be held on the spindle by the cord. Is this correct? When changing wavebands the dial slips and eventually indicates the wrong band. Should the plastic dial be held in place by any other means other than the cord?. Help appreciated. Thanks

27th Jan 2022, 4:39 pm	#2
greencroft Triode Join Date: Jan 2022 Location: Hexham, Northumberland, UK. Posts: 24	Re: PYE P76F Wave Change Quick update. When wave switch in short wave position there is zero tension on spring holding one end of drive cord. Spring tension increases as switch moved to G position. Anyone know what the correct tension should be?

27th Jan 2022, 5:05 pm	#3
Cobaltblue Moderator Join Date: Dec 2010 Location: Exeter, Devon and Poole, Dorset UK. Posts: 6,879	Re: PYE P76F Wave Change From the manufactures service sheet available above. https://www.service-data.com/product...11/6662/m15211 Cheers Mike T Attached Thumbnails __________________ Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk

27th Jan 2022, 6:32 pm	#4
greencroft Triode Join Date: Jan 2022 Location: Hexham, Northumberland, UK. Posts: 24	Re: PYE P76F Wave Change Mike I have the service sheet which shows route of cord but nothing about correct tension. Also should it be silicon lubricated or wax. Or dry

27th Jan 2022, 6:52 pm	#5
PYE 405 Pentode Join Date: Dec 2009 Location: Chatteris, Cambridgeshire, UK. Posts: 176	Re: PYE P76F Wave Change Hi, I don't think that there is a specific tension as such, but with mine I simply adjusted it so that the spring only just held the wire taught at the most relaxed position (SW). The indicator should of course be able to rotate freely on it's spindle, but I can't see any need to apply wax or silicone to the wire. It is possible that the wire might have stretched slightly, so it may be a good idea to check the length according to the data rather than alter the actual spring. __________________ Andrew Last edited by PYE 405; 27th Jan 2022 at 7:13 pm.

27th Jan 2022, 7:23 pm	#6
PYE 405 Pentode Join Date: Dec 2009 Location: Chatteris, Cambridgeshire, UK. Posts: 176	Re: PYE P76F Wave Change Just to add to the above, I do believe there is a small notch that the wire passes through on the plastic indicator shaft. This probably serves as a securing point, but if worn, perhaps a very small dab of glue may help to keep the indicator from slipping due to the action of abrupt switch rotation. __________________ Andrew

27th Jan 2022, 9:00 pm	#7
greencroft Triode Join Date: Jan 2022 Location: Hexham, Northumberland, UK. Posts: 24	Re: PYE P76F Wave Change Andrew, thanks for the info. My cord is not going through any notch on the plastic dial it's just wrapped around the dial

27th Jan 2022, 9:56 pm	#8
PYE 405 Pentode Join Date: Dec 2009 Location: Chatteris, Cambridgeshire, UK. Posts: 176	Re: PYE P76F Wave Change If your set has a cord instead of wire, then perhaps it was replaced I wonder. It could have been fitted from new though, especially as there is no notch in the indicator shaft. In that case, a waxed cord might offer better grip than one without. __________________ Andrew

27th Jan 2022, 11:26 pm	#9
greencroft Triode Join Date: Jan 2022 Location: Hexham, Northumberland, UK. Posts: 24	Re: PYE P76F Wave Change Andrew there is a notch just that the cord isn't going through it. It is now. Also it is cord not wire. Thanks for the info. Ken

9th Feb 2022, 10:18 am	#10
greencroft Triode Join Date: Jan 2022 Location: Hexham, Northumberland, UK. Posts: 24	Re: PYE P76F Wave Change Update re wavechange switch it appears the relaxed position is not Shortwave on my set BUT G. Bluetooth works through the Shortwave selection and Longwave is TB.!!

9th Feb 2022, 1:32 pm	#11
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,887	Re: PYE P76F Wave Change Take a look at your other post, which I answered. John

11th Feb 2022, 10:11 am	#12
greencroft Triode Join Date: Jan 2022 Location: Hexham, Northumberland, UK. Posts: 24	Re: PYE P76F Wave Change Thanks for reply. Problem due to cord wound back to front.