|
Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
|
Thread Tools |
11th Oct 2019, 6:34 am | #1 |
Moderator
Join Date: Feb 2006
Location: Wembley, Middlesex
Posts: 7,224
|
Grundig Como 5/GB radiogram
I have been working on this Grundig radiogram.
VHF reception is fine, but on all AM bands, LW, MW, SW, all I get is constant static noise with no stations being able to be tuned in. Has anyone any suggestions as to why? |
11th Oct 2019, 8:15 am | #2 |
Heptode
Join Date: Sep 2010
Location: Hythe, Hampshire, UK.
Posts: 630
|
Re: Grundig Como 5/GB radiogram
Have you checked to see if the local oscillator is running in the LW, MW, SW frequency changer section, could be a faulty component, valve, broken wire etc.
|
11th Oct 2019, 7:03 pm | #3 |
Octode
Join Date: Feb 2007
Location: Harrow, London, UK.
Posts: 1,493
|
Re: Grundig Como 5/GB radiogram
Hi Michael
From your previous threads you have some experience in repairing radios so I won't tell you to replace the valve, which of course you would be hard to find! Looking at the schematic, there is nothing unusual about the am front end. I don't have picture of the am tuning capacitor but I imagine it would it be an open vane version. No chance a drop of solder has shorted out the oscillator gang? As short wave is also dumb, the ferrite rod connections won't be the cause. I guess you have checked the dc conditions on T11/12 so the next thing to do would be to get out your signal generator and work backwards. Chris |
11th Oct 2019, 11:07 pm | #4 |
Moderator
Join Date: Feb 2006
Location: Wembley, Middlesex
Posts: 7,224
|
Re: Grundig Como 5/GB radiogram
Its not a valved set, fully transistorised. I'll look at it when I get back in a week or two.
|