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| Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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16th Sep 2023, 10:33 am
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#1 |
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Hexode
Join Date: Mar 2009
Location: Cirencester, Gloucestershire, UK.
Posts: 390
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Resistors used in the Magnavox 300TR
Hello All
I have a Magnavox 300TR transistor radio of 1960 and it uses the type of resistors shown in the attached photo. Can anyone please help me who may have manufactured these resistors. There seem to be some opinions that the radio was built by Plessey and so I suppose they are a candidate. best regards ... Stef |
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16th Sep 2023, 10:47 am
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#2 |
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Dekatron
Join Date: Sep 2003
Location: Near Swindon, North Wiltshire, UK.
Posts: 3,492
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Re: Resistors used in the Magnavox 300TR
They were made by Erie in the UK, as were the light blue ceramics.
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16th Sep 2023, 11:02 am
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#3 |
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Hexode
Join Date: Mar 2009
Location: Cirencester, Gloucestershire, UK.
Posts: 390
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Re: Resistors used in the Magnavox 300TR
Many thanks.
I didn't realise that the light blue components were capacitors. How does their colour code read? |
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16th Sep 2023, 11:07 am
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#4 |
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Hexode
Join Date: Mar 2009
Location: Cirencester, Gloucestershire, UK.
Posts: 390
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Re: Resistors used in the Magnavox 300TR
Looking at the schematic, I think they are a low value feedback (neutralising?) capacitors used in the IF stages, see the attached detail.
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16th Sep 2023, 11:25 am
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#5 | |
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Dekatron
Join Date: Sep 2003
Location: Near Swindon, North Wiltshire, UK.
Posts: 3,492
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Re: Resistors used in the Magnavox 300TR
Quote:
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16th Sep 2023, 12:15 pm
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#6 |
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Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,465
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Re: Resistors used in the Magnavox 300TR
Yes Erie is the name that comes to mind.
They have a bit of a poor reputation, the stamped brass end ferrules tend to split lengthways and lose their grip on the carbon stick.
__________________
I played a blank tape at full volume. The mime-artiste who lives next door complained. |
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16th Sep 2023, 8:20 pm
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#7 |
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Dekatron
Join Date: Sep 2003
Location: Near Swindon, North Wiltshire, UK.
Posts: 3,492
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Re: Resistors used in the Magnavox 300TR
Here are some examples the Erie carbon composition PCB mounting resistors:
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17th Sep 2023, 9:44 am
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#8 |
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Hexode
Join Date: Mar 2009
Location: Cirencester, Gloucestershire, UK.
Posts: 390
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Re: Resistors used in the Magnavox 300TR
If you could post the Erie resistor and capacitor datasheets, it would be most appreciated.
best regards ... Stef |
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17th Sep 2023, 10:35 am
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#9 | |
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Dekatron
Join Date: Sep 2003
Location: Near Swindon, North Wiltshire, UK.
Posts: 3,492
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Re: Resistors used in the Magnavox 300TR
Quote:
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17th Sep 2023, 11:59 am
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#10 |
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Dekatron
Join Date: Sep 2003
Location: Near Swindon, North Wiltshire, UK.
Posts: 3,492
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Re: Resistors used in the Magnavox 300TR
And the PCB ceramic capacitors (Erie UK, later taken over by ITT)....
I also attach a sheet from several Erie/ITT capacitor catalogues, showing the variations in margins over the years. I think the 1972 Erie catalogue is the one that covers the two shown in your PCB photo and it looks like they decode as 25pF and 13pF. |
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18th Sep 2023, 10:22 am
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#11 |
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Hexode
Join Date: Mar 2009
Location: Cirencester, Gloucestershire, UK.
Posts: 390
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Re: Resistors used in the Magnavox 300TR
Many thanks for the Erie data, it's just what I need.
best regards ... Stef |
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