26-10-2017, 06:12 PM
Yes, this is the problem. As your FY2200S generator doesn't do AM, we can't test as nicely as we'd like. It's possible that we'd hear an audible "click" as you connect and disconnect the generator, or that you'd see a DC voltage at the detector diode, but a nice AM source is what we really need because it means you can use your ears. Sorry I can't give specific recommendations - there's lots to choose from. Perhaps have a look on eBay and start a new thread asking for our opinions?
Interesting that you mention an AF114. These sets were originally built with AF117s, so that transistor is a replacement. Have you looked to see if it has tin whiskers? When not in the circuit, just check with your meter for resistance between the wires and the can. Ignoring the screen lead - for obvious reasons - the resistance between the can and the other leads should be infinite according to your DMM. If not the case, you'll need to "zap" them. Forgive me if I've already posted this link, but here's what I do: http://www.markhennessy.co.uk/articles/v...with_af11x
As I explained earlier, the diode is inside the IFT. Unless you remove the IFT and take it apart, you can't get to both ends of the diode.
To give you a better idea of what I'm trying to convey, take a look at the attachments. These show a different unit (from the FM IF PCB), but you should get the idea. There are more components in here, but there's more space as the coil is only a single one (IFTs have 2, and are surrounded by a ferrite outer which occupies most of the space). This particular one is related to the ISM feature on AM, and this one did have a faulty diode, but as far as I (or my photo collection) can recall, this is the only diode I've changed in a Hacker IFT.
Interesting that you mention an AF114. These sets were originally built with AF117s, so that transistor is a replacement. Have you looked to see if it has tin whiskers? When not in the circuit, just check with your meter for resistance between the wires and the can. Ignoring the screen lead - for obvious reasons - the resistance between the can and the other leads should be infinite according to your DMM. If not the case, you'll need to "zap" them. Forgive me if I've already posted this link, but here's what I do: http://www.markhennessy.co.uk/articles/v...with_af11x
As I explained earlier, the diode is inside the IFT. Unless you remove the IFT and take it apart, you can't get to both ends of the diode.
To give you a better idea of what I'm trying to convey, take a look at the attachments. These show a different unit (from the FM IF PCB), but you should get the idea. There are more components in here, but there's more space as the coil is only a single one (IFTs have 2, and are surrounded by a ferrite outer which occupies most of the space). This particular one is related to the ISM feature on AM, and this one did have a faulty diode, but as far as I (or my photo collection) can recall, this is the only diode I've changed in a Hacker IFT.
