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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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19th Feb 2021, 7:15 pm | #1 |
Hexode
Join Date: Oct 2006
Location: Edenderry, Republic of Ireland.
Posts: 428
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Vidor CN429, no life.
Hi again, Have a Vidor CN429with no stations coming through. All valves are OK as is the output transformer and speaker. I do not have any HT going from L7 to pin 2 of V2 of the 2nd IF transformer. Does this mean that the 2nd IF transformer is gone O/C? Any help would be very much appreciated. Dick.
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19th Feb 2021, 8:03 pm | #2 |
Octode
Join Date: Mar 2020
Location: Blackburn with Darwen, Lancashire, UK.
Posts: 1,573
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Re: Vidor cn429 no life
looking at the circuit it would suggest that is the case. Assuming you have checked for dry/bad joints and that one side of L7 has volts and the other not then it looks to be open circuit.
If lucky you may find a broken wire within the can that can be repaired if it is at a connection point. I am not seeing any grid cap that if it was leaking would seriously up the anode current, so can only guess it is a vibration or dropped radio issue? Just my thoughts of course, I could be missing something obvious. Adrian |
23rd Feb 2021, 9:26 pm | #3 |
Hexode
Join Date: Oct 2006
Location: Edenderry, Republic of Ireland.
Posts: 428
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Re: Vidor cn429 no life
Hi again, I salvaged an I.F can from a Lady Catherine, now the difference was that one side measured 29 ohms and the other 21 ohms. both had 65pf caps. I am now getting R.T.E. radio on L.W. very clear but very low on full volume. was it possible to insert the can wrong way round.Any help would be very much appreciated. Dick
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23rd Feb 2021, 9:33 pm | #4 |
Dekatron
Join Date: Feb 2009
Location: Chesterfield, Derbyshire, UK.
Posts: 3,767
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Re: Vidor cn429 no life
Did you inspect the old one ,looking for broken wire. was it the second if can you replaced it with. Mick.
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24th Feb 2021, 3:07 pm | #5 |
Hexode
Join Date: Oct 2006
Location: Edenderry, Republic of Ireland.
Posts: 428
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Re: Vidor cn429 no life
Hi Mick, yes it was the second I.F. I replaced it with. When I took the old can asunder the wires were intact but I had no continunity on either coil. Dick.
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24th Feb 2021, 4:57 pm | #6 |
Hexode
Join Date: Oct 2006
Location: Edenderry, Republic of Ireland.
Posts: 428
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Re: Vidor CN429, no life.
Hi again,should I have continuity through L 5 L 6, L7 and L 8 without power switched on. I have ohm readings on L5 L 7 and L8 but no reading on L 6. Thanks again Dick.
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6th Mar 2021, 4:46 pm | #7 |
Hexode
Join Date: Oct 2006
Location: Edenderry, Republic of Ireland.
Posts: 428
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Re: Vidor CN429, no life.
Hi again, I have had to replace the 1st I.F transformer as well as the second I.F in the set. I now have radio 1(eireann) coming in with lots of volume but at the very end of the wave band. Does this mean that the new transformers need to be reset or could it be some other fault. I have a velleman k700 signal tracer. Would it do to calibrate the set. Any advice would be very much appreciated. Dick.
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6th Mar 2021, 5:23 pm | #8 |
Heptode
Join Date: Jan 2006
Location: Cornwall, UK.
Posts: 506
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Re: Vidor CN429, no life.
Having a strong signal in the wrong place on the dial indicates the local oscillator needs adjustment, however, with both IF transformers having been replaced full alignment with a signal generator is the ideal approach. If you put "alignment without instruments" into the search box you will find ways of improving matters.
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