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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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15th Dec 2017, 6:07 pm | #21 |
Rest in Peace
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Location: Basildon, Essex, UK.
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Re: Toaster FB10 elusive fault
I may still have a spare ferrite rod aerial for one of these, but I dont think it will be better than the frame aerial, frame aerials are quite efficient. You could test the windings for continuety on the frame to see if there is a problem.
Mike |
17th Dec 2017, 4:33 pm | #22 |
Octode
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Location: Sheffield, South Yorkshire, UK.
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Re: Toaster FB10 elusive fault
The coils are not shorting together as far as I can tell .I will re-examine tonight .It seemed to me that the sudden change in volume , odd whistles and weak interference from MW stations on LW pointed towards an aerial fault , but I am grasping at straws here. I measured 0.1 ohms and 1 ohm with cheap DMM for the L1 and L2.
The original 6BA6 (45% on test )valve was substituted with a new one and no change noticed . |
18th Dec 2017, 12:02 am | #23 |
Dekatron
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Re: Toaster FB10 elusive fault
Next time the fault occurs carefully check the tuning (assuming that altering the tuning doesn't clear the fault....). See if the tuning has changed....i.e is it 'broader' (the tuned station taking up more room on the scale). If so, it could be something subtle like a capacitor going O/C in one of the IF coils. This could certainly cause crackling and a reduction in volume since the IF transformer won't be tuned to the correct IF frequency when the cap is O/C.
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18th Dec 2017, 12:19 am | #24 |
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Re: Toaster FB10 elusive fault
Sideband's got a point. As previously mentioned ..... if you are concerned about using freezer spray ..... think about some hot air?
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18th Dec 2017, 3:55 am | #25 |
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Re: Toaster FB10 elusive fault
As a method for repair, I have never found modifying a set to be the best answer, only a last resort solution.
Changing to a ferrite rod seems to be a lot of work with little guarantee that it will solve the problem, a defect in a frame aerial should be obvious and repairable. |
18th Dec 2017, 12:17 pm | #26 |
Dekatron
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Re: Toaster FB10 elusive fault
Agreed... and it's very unlikely that there will be a fault with the frame aerial anyway... certainly nothing to cause burn marks (there is nowhere near enough current anywhere to do that) although of course it could have been damaged by careless handling or a soldering iron at some time.
All I can say is that my FB10 works very acceptably on it's frame aerial.
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18th Dec 2017, 1:09 pm | #27 | |
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Re: Toaster FB10 elusive fault
Quote:
Its not loose cores in an IF trany is it? |
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18th Dec 2017, 10:33 pm | #28 |
Dekatron
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Re: Toaster FB10 elusive fault
...as I alluded to a few posts back. The problem (if it is an internal tuning cap failing) is deciding which one. Usually if the internal cap fails, the tuning slug has little or no effect or it has to be screwed fully in or out.
As far as I am aware they are just standard ferrite tuning cores so not likely to be a detached core.
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There are lots of brilliant keyboard players and then there is Rick Wakeman..... |
21st Dec 2017, 2:27 pm | #29 |
Octode
Join Date: Jun 2005
Location: Sheffield, South Yorkshire, UK.
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Re: Toaster FB10 elusive fault
The burning on aerial was caused by the very close rectifier and output valves. For now , it is going back in its box. Thanks for all the advice.
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