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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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16th Feb 2010, 6:33 pm | #1 |
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advice please with pilot 75
the radio works loud and clear on short wave very weak on medium wave and weaker as you tune up the scale and nothing on long wave.the caps have been changed and the valve pins cleaned.where should I be looking .
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16th Feb 2010, 6:42 pm | #2 |
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Re: advice please with pilot 75
Clean the wavechange switch thouroughly. Measure all the coils on the Front End. Tweak the front end coils a little.
C1. C4. C8. C9 - If you haven't done so already. Check the valve of course and try a big aerial. Cheers, Steve P.
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16th Feb 2010, 6:43 pm | #3 |
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Re: advice please with pilot 75
Hi
This type of fault is usually caused by the coupling of the local osc back into the mixer being poor, usually a mica type cap that has gone low value, also the aerial coil coupling cap (again usually a low value mica) again going low value, the high frequencies can pass ok but little or nothing on Long Waves. Cheers Trevor
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17th Feb 2010, 9:09 pm | #4 |
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Re: advice please with pilot 75
thanks for your help changing caps 4 and 8 has has now given the radio a decent medium wave tuning stations that were unavailable before. I still have no action on long wave the radio has no life at all on this wavelength I have used contact cleaner on the wavechange switch and caps 1 and 9 had already been changed,it was enjoyable hearing the medium wave come to life I am learning all the time.
thanks again john. |
17th Feb 2010, 9:24 pm | #5 |
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Re: advice please with pilot 75
Does the oscillator work on LW? If yes, check L4, C3. If no, C32, L9.
Put the aerial on C4/Grid of the 7S7 (Pin 6) and see if it comes in on LW there. Cheers, Steve P.
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If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...? |
19th Feb 2010, 6:48 pm | #6 |
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Re: advice please with pilot 75
hi
long wave comes to life with the aerial on pin 6, C3 has been changed still no long wave I do not know how to check L4. cheers john. |
19th Feb 2010, 8:23 pm | #7 |
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Re: advice please with pilot 75
L4 is the longwave loading coil, it should have a resistance of about 9.5 ohms according to the trader sheet. It is the coils along with l5 to the right of the tuning cap as you look at the front of the chassis
cheers mark |
19th Feb 2010, 11:27 pm | #8 |
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Re: advice please with pilot 75
hi
one side is 1.9 ohms I assume this is L5 as this is 1.7 ohms according to the trader sheet and L4 has a resistance of 3.5 ohms thanks john. |
19th Feb 2010, 11:37 pm | #9 |
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Re: advice please with pilot 75
On all settings of the wavechange switch?
If it's OK, try tweaking C32 and C26. Note where they were first. The RF alignment is on the sheet - it may be worth doing IF then RF alignment. Cheers, Steve P.
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If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...? |
19th Feb 2010, 11:59 pm | #10 |
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Re: advice please with pilot 75
when longwave is selected L4 reads 12.5 ohms
thanks john. |
20th Feb 2010, 12:01 am | #11 |
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Re: advice please with pilot 75
Should be OK. Try full realignment.
Cheers, Steve P.
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If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...? |
20th Feb 2010, 11:59 am | #12 |
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Join Date: Jan 2010
Location: Bishop Auckland, County Durham, UK.
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Re: advice please with pilot 75
wow! joy a tweak on C32 and the radio talks to me on longwave and a tweak on C26 gives improved medium reception thanks for the help,I have learnt a bit more.
thanks john. |