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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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25th Feb 2021, 5:43 pm | #1 |
Heptode
Join Date: Nov 2018
Location: Staffordshire Moorlands, UK.
Posts: 595
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HMV 1120 Exceptional MW no LW
I have just replaced a few caps and now have exceptional MW signal but no LW; any ideas where to start searching for the problem please.
There was no LW reception prior to changing the caps. Thank you. |
25th Feb 2021, 6:36 pm | #2 |
Dekatron
Join Date: Feb 2009
Location: Chesterfield, Derbyshire, UK.
Posts: 3,767
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Re: HMV 1120 Exceptional MW no LW
Check if the osc is running first , do you have a scope , or if I remember correctly meter the cathode of the osc valve short the ocs tuning capacitor to chassis , the volts should increase if it's oscillating , Mick.
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25th Feb 2021, 9:27 pm | #3 |
Heptode
Join Date: Nov 2018
Location: Staffordshire Moorlands, UK.
Posts: 595
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Re: HMV 1120 Exceptional MW no LW
Thanks Mick, yes I have a scope but as yet have not familiarised myself as to how to operate but will do as you suggest.
Thank you. |
25th Feb 2021, 9:55 pm | #4 |
Dekatron
Join Date: Feb 2009
Location: Chesterfield, Derbyshire, UK.
Posts: 3,767
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Re: HMV 1120 Exceptional MW no LW
Hi Brian ,time to get familiar with the scope ,switch to mw , try and find a sinewave on one of the sections on the tuning capacitor , it will vary with the tuning , then switch to l/w and see if you have a waveform on the same part of the tuning capacitor ,hope this makes sense, Mick.
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1st Mar 2021, 7:46 pm | #5 |
Heptode
Join Date: Nov 2018
Location: Staffordshire Moorlands, UK.
Posts: 595
|
Re: HMV 1120 Exceptional MW no LW
Yes, all makes sense Mick, will give it a try after getting used to scope.
Thank you. |