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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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6th May 2019, 9:49 pm | #1 |
Pentode
Join Date: Feb 2015
Location: Belfast, Northern Ireland, UK.
Posts: 130
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Hacker Herald noisy
My LW/MW Hacker Herald has developed a noisy output as if someone was blowing across the studio microphone. I thought it might be a bad contact at the 5pin plug or the wave change switch or even the volume or pots for bass and treble but gentle cleaning and contact cleanser hasn’t helped. Can anyone help me in looking further? The radio is receiving all stations normally but just has this annoying rumble in the background which can only be minimised by winding the bass back fully.
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6th May 2019, 10:31 pm | #2 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,788
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Re: Hacker Herald noisy
Does the noise vary with the volume control or is it at a constant level?
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6th May 2019, 10:32 pm | #3 |
Hexode
Join Date: Mar 2018
Location: Bishop Auckland, County Durham, UK.
Posts: 373
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Re: Hacker Herald noisy
The problem is almost certainly caused by transistor T1 on the bottom audio panel. A BC108 can be used as a replacement.
Post crossed with Paul's
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Regards Martin |
6th May 2019, 10:38 pm | #4 |
Pentode
Join Date: Feb 2015
Location: Belfast, Northern Ireland, UK.
Posts: 130
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Re: Hacker Herald noisy
The noise is constant and not dependent on volume setting.
Thank you to both Paul and Martin. I’ll source another BC148 or a BC108 as you suggest. |
6th May 2019, 10:44 pm | #5 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,788
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Re: Hacker Herald noisy
Don't use another BC148 Lockfit. Use a different BC108 family transistor like a BC548. This is just a general purpose transistor and lots of other types will also work - 2N2222, 2N3904 etc.
https://en.wikipedia.org/wiki/BC108_family Lockfits are commonly failing now and a forum search will find lots of threads about them. |
7th May 2019, 11:22 am | #6 |
Octode
Join Date: Dec 2010
Location: St Ives, Cambridgeshire, UK.
Posts: 1,180
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Re: Hacker Herald noisy
Which Herald is it? RP10, RP30 or RP35?
Andrew
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Invisible airwaves crackle with life. Or they should do. BVWS Member |
7th May 2019, 8:19 pm | #7 |
Pentode
Join Date: Feb 2015
Location: Belfast, Northern Ireland, UK.
Posts: 130
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Re: Hacker Herald noisy
Andrew, it’s a MW/LW Herald RP35 and thanks to Paul and Martin’s advices I have replaced T1 with a BC108 and it now sounds great!! Just the way a Hacker should. Thanks boys.
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