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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
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16th Sep 2019, 9:37 pm | #1 |
Heptode
Join Date: Jun 2012
Location: Southeast Norfolk, UK.
Posts: 773
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Wearite BFO coil?
Hi All,
I have a plug-in BFO unit, which is U/S, fitted in a Coastal Radio 91/MX marine receiver. The 91/MX IF is 470kHz and the single coil was made by Wearite, but unfortunately the type markings are too faded to read. I suspect the coil is O/C but need to lift some of the connections to do a proper continuity test. However I have not been able to find any info online for a Wearite coil for a BFO application, so I was wondering if anyone had a catalogue or data sheet with more info, probably from the late 40s/early 50s era? Thanks, Roger |
17th Sep 2019, 8:07 am | #2 |
Dekatron
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,761
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Re: Wearite BFO coil?
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David. BVWS Member. G-QRP Club member 1339. |
17th Sep 2019, 5:51 pm | #3 |
Heptode
Join Date: Jun 2012
Location: Southeast Norfolk, UK.
Posts: 773
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Re: Wearite BFO coil?
Thanks David, I can't see a BFO coil as such on that page but it helps to know what the various Wearite coils were used for.
73 Roger |
17th Sep 2019, 5:59 pm | #4 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Wearite BFO coil?
You won't see a picture of it on the page or shown in the tables but it's described in the text, basically a 1000uH inductor tapped for Hartley osc operation, for an IF of 465kHz a capacitor of 118pF will give a 1kHz beat note.
Lawrence. |
18th Sep 2019, 6:42 am | #5 |
Heptode
Join Date: Jun 2012
Location: Southeast Norfolk, UK.
Posts: 773
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Re: Wearite BFO coil?
You're absolutely right, Lawrence! I had looked at the drawings of the coils and the table. With that info I can probably wind a replacement coil if the original turns out to be O/C.
Many thanks, Roger |
19th Sep 2019, 11:46 am | #6 |
Heptode
Join Date: Jun 2012
Location: Southeast Norfolk, UK.
Posts: 773
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Re: Wearite BFO coil?
OK, got a little further with the coil problem. Removing the Wearite coil from the chassis reveals the part number is a PO7, an oscillator coil with two windings. One winding appears O/C. No sign of a PO7 on ebay or other sites so does anyone have one in their collection they will sell?
Cheers Roger |
25th Sep 2019, 1:47 pm | #7 | |
Heptode
Join Date: Jun 2012
Location: Southeast Norfolk, UK.
Posts: 773
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Re: Wearite BFO coil?
Quote:
Thanks Roger |
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