HMV 1360 receiver.

[_Garak_]

Picked this up recently.

An H.M.V model 1360 from the 50's. It shows no sign of life and is not drawing any current.

It's in pretty good condition and the Bakelite case will clean up nicely.

I will do dome diagnosis and will change all of the 'waxy' caps and perhaps some 'dog-bone' resistors. I'm hoping the mains transformer is good.

I've already obtained a schematic.

First job, break out a can of 'Air duster'

[_Garak_]

[_Garak_]

Sorry, no mains transformer, its an AC / DC set.

[cathoderay57]

I recommend you check the resistances of the tall mains dropper, all sections, as well. Jerry

[Station X]

Originally Posted by _Garak_

It shows no sign of life and is not drawing any current.

I'm not sure how you know it's drawing no current, but it could be something as simple as a blown fuse in the plug or a dodgy OFF/ON switch.

I'd get the set's internal power supply arrangements sorted out before starting to change capacitors.

[_Garak_]

Originally Posted by Station X

I'm not sure how you know it's drawing no current, but it could be something as simple as a blown fuse in the plug or a dodgy OFF/ON switch.

I'd get the set's internal power supply arrangements sorted out before starting to change capacitors.

When I first powered up the set it was through a lamp current limited device,



After I has cleaned the chassis of all of the dust I discovered that one of the 500ma mains input fuses had blown, after that was changed the set powered up through the current limiter and all of the tube heaters lit up and the dial lamps illuminated so I assumed the set did not have a major short. I then powered up the set again this time through my Hopi meter and the set draws around 49w.

The set does not find any stations but a lot of static is heard on the LW setting. I have downloaded a couple of circuit schematics for this set and the Sobell 515 which is identical to the H.M.V. Unfortunately the schematic for the H.M.V. is in very low resolution. The component layout is impossible to understand due to the resolution and the Sobell schematic does not have a component layout diagram.

Does anyone have a good resolution of the underside component layout so I can identify and cross reference component values.

[McMurdo]

for £1.99 you can get a quality downloadable copy of the original service manual from this forum's service data service.

https://www.service-data.com/product...96/3697/m18896

[Edward Huggins]

ER, did I read above that the Sobell 515 is identical to yours?!

[Station X]

Originally Posted by McMurdo

for £1.99 you can get a quality downloadable copy of the original service manual from this forum's service data service.

https://www.service-data.com/product...96/3697/m18896

I can confirm that. The service info linked to contains a legible under chassis layout.

I would suggest that the OP takes voltage readings on the valves in the set and compare them with those in the service sheet. If he posts the readings here he'll undoubtedly find someone willing to interpret the readings for him.

Cleaning the contacts of the wave change switch with Servisol 10 contact cleaner may help.

[Station X]

Originally Posted by Edward Huggins

ER, did I read above that the Sobell 515 is identical to yours?!

Yes you did read that in post #1. What is your point? Do you disagree?

[_Garak_]

I have replaced 90% of the set's waxy capacitors and all of the electrolytic capacitors but I still could not tune any stations.

It was suggested to me that the oscillator was perhaps not working so I measured the voltages from Valve 1 (X142) and Valve 2 (W142) and got some anomalous readings

Valve 1 pin2 172v (should be 185v) pin3 64.5v (should be 95v) pin5 65v (should be 66v)

Valve 2 pin2 172v (should be 185v) pin5 79v (should be 78v)

Afterwards I was poking around with an insulated probe looking for loose wires and bad solder joints when I tapped on the top of component TC6 (long wave oscillator coil) and the humming and crackling increased dramatically. Now by putting pressure on top of the coil I am able to tune a BBC station in the LW section at around 1475m

Tapping on TC4 (SW coil) produced the same higher volume but I was unable to tune any stations on the SW band.

Tapping on TC5 (MW coil) made no difference and no MW stations could be tuned.

Here is TC6:



And a video:

https://youtu.be/Yv6ZvFn-l_k

Can anyone tell me if the valve voltages are within tolerance? and what can be done to rectify the coil problem?

[_Garak_]

Here is the schematic:

[PJL]

I doubt it is the coil, more likely to be a poor connection elsewhere. Clean the waveband switch and the valve pins again.

[PaulR]

If you have replaced several components that connect to the same tag make sure that the solder has run down to all the leads on the tag. It is very easy to get the top lead soldered nicely but to leave a lead or leads below that unsoldered.

[ronbryan]

Those HMV concentric trimmers are notorious for going short circuit.

Ron