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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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5th Jul 2020, 7:39 pm | #1 |
Diode
Join Date: Apr 2020
Location: Wokingham, Berkshire, UK.
Posts: 7
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PW 208 Bandspread Portable restoration - alignment
Hi
Further info from a previous post inc circuit diags. See https://www.vintage-radio.net/forum/...d.php?t=168193 I have changed the electrolytic caps as suggested in the previous post but with no improvement in performance of the radio. I even temporarily replaced the RF stages decoupling caps with no improvement either. However re alignment has been much more successful and the set is working reasonably on MW. I have never aligned a radio before and I started by aligning the IFTs to 470KHz using a Digimess SG100 sig gen. IFT 1 and 2 peaked with just a little tweek of the slug however IFT 3 is no where near as sensitive and I can twiddle the core quite a lot both up and down with no sensitive spot like I obtained with IFT1 and 2. On IFT3 should I get the same sensitivity as IFT1 and 2? |
5th Jul 2020, 8:20 pm | #2 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,433
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Re: PW 208 Bandspread Portable restoration - alignment
If IFT3 feeds the detector it will not be as “peaky” But would expect some rise when on tune.
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Frank |
5th Jul 2020, 8:50 pm | #3 |
Rest in Peace
Join Date: Mar 2011
Location: Basildon, Essex, UK.
Posts: 4,100
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Re: PW 208 Bandspread Portable restoration - alignment
Have you tried turning the signal generator output right down so you can hardly hear it.
Mike |