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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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8th Jun 2019, 11:24 am | #1 |
Tetrode
Join Date: Mar 2018
Location: Amsterdam, Netherlands
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What's inside? - Mullard module 1402
My new Roberts R505 has good reception on AM; FM is rather weak.
Does anyone know, what hides inside the Mullard module 1402/02? - I can find a lot of guessing, but nobody seems to know... Are there really AF11x transistors lurking in it? |
8th Jun 2019, 11:33 am | #2 |
Dekatron
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Re: What's inside? - Mullard module 1402
Very likely,I think.
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G8JET BVWS Archivist and Member V.M.A.R.S |
8th Jun 2019, 1:02 pm | #3 |
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Re: What's inside? - Mullard module 1402
The manufacturer's service manual (available 'up top') includes the internals of this module on the full circuit diagram, but with no component values given.
It shows it contains a pair of NPN transistors, which I would think were unlikely to be AF11x's (or indeed germanium at all). |
8th Jun 2019, 1:06 pm | #4 |
Tetrode
Join Date: Mar 2018
Location: Amsterdam, Netherlands
Posts: 68
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Re: What's inside? - Mullard module 1402
I did see this on the service manual, no details about the transistors.
Maybe someone had a peek in the module though... |
8th Jun 2019, 1:18 pm | #5 |
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Re: What's inside? - Mullard module 1402
Apologies,I have the wrong Mullard module type.
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G8JET BVWS Archivist and Member V.M.A.R.S |
8th Jun 2019, 1:39 pm | #6 |
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Re: What's inside? - Mullard module 1402
If they are NPN transistors then they are likely to be BF194/5 Lockfits.
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8th Jun 2019, 1:49 pm | #7 |
Tetrode
Join Date: Mar 2018
Location: Amsterdam, Netherlands
Posts: 68
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Re: What's inside? - Mullard module 1402
No AF11x then, no PNP
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9th Jun 2019, 6:04 pm | #8 |
Tetrode
Join Date: Mar 2018
Location: Amsterdam, Netherlands
Posts: 68
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Re: What's inside? - Mullard module 1402
We will not know what is inside the module, it seems, at least not for the time being.
What helps in the case of my radio is the proper voltage. The battery in my radio was quite tired I found out, when I eventually took the trouble to measure it. Now the radio is connected to the power supply, the display says 8.93 Volts, 20 mA. All is well therefore: VHF also. |