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It might make a good filter for a radio with a 9 MHz IF. None of mine use that frequency. 73, Maynard W6PAP

I didn't have this radio when I ordered the filter.? I ordered it on the off-chance I could get it to work in my Heathkit DB-303 receiver. 73, -- Justin B. KI5GKD

Hi, Justin, The point where the "extra" contact is located in the 8R-40 is following demodulation and is at audio frequencies where the 9 MHz filter on Aliexpress would not work. Most commercial

Hi, Justin, The point where the "extra" contact is located in the 8R-40 is following demodulation and is at audio frequencies where the 9 MHz filter on Aliexpress would not work. Most commercial

DonThe load on the transformer is meaningless since the primary is fed with 31 volts instead of 120 volts RMS.? Since power is proportional to voltage squared, no real work is being done, nothing is

Maynard - What about something like this?? I ordered it when I was ordering a couple other odds-and-ends and it was pretty

Halden, you must have the ears of an owl ! Why not try a small well insulated wire at the end of a scope probe, to act as a local capacitor coupling, and see if some rf “jumps” onto the

Hi Jim , I believe your description, but you seem to have glossed over the fact that Halden’s tests had a load on the transformer secondary, and that can’t be ignored. if you remove the load,

The transformer winding failed due to bad insulation/damaged insulation and/or a bad bit of copper, IE: the copper had a small impurity that caused heat, and the insulation, which is about 80 years

<grins>JimLogic: Method used to arrive at the wrong conclusion, with confidence.? Murphy

Yes, the tone control switch disables AVC when set to "C.W." I prefer the independence of control that the S-40B provides. But one advantage of the 8R-40 might be the open switch contact on the tone

Hi Don, It's abundantly clear to me that your comments are meant to contribute to the conversation and to my progress in understanding how all this works.? Hopefully a few spectators are learning

I opened up the transformer to see if I might be able to repair it.? So far, it appears to have been wound as Jim described: Primary first HV secondary 2nd Filament windings last.? I haven't peeled

I have also read that some of the artificial sweeteners cause gastric problems.? In any of the drinks I make I use either Stevia or Monk Fruit extract. Justin B. - KI5GKD

Not much. I don't drink much soda of any sort and don't use lo-cal sweeteners (or sugar for that matter). I don't think I can blame my bad memory on that. Curiously my memory is very good for some

HaldenYou said: "By transitivity, then, primary current and primary voltage are in phase with each other." No, this violates all that is known about inductors and coupled inductors aka transformers.?

DonThere is no difference between two inductors and a transformer if the two inductors are coupled together only by a common magnetic field.? The tighter the coupling between the two inductors, the

Hi Richard, Do you drink ANYTHING with Aspartame? The non-caloric sweetener? It's found in many Diet Soft Drinks and in table packets (Brand name Nutrasweet and Equal). I was having issues exactly

Hi Jim, The purpose of monitoring primary current is to understand how the transformer's operation affects the power source.? The purpose of monitoring secondary voltage is to understand how the

Hi jim I think many and me/I would agree with paragraph 2, and 3, but on pgf 1, with all due respect, this is a transformer, and it has some resistive load which is reflected to the primary as-in