开云体育

I have one of those little testers.? Capacitor checks seem to be close to what my much older Sencore LC75 meter shows.?? The Sencore meter will check leakage at various voltages. Not able to do

Matteo, you are not crazy but you must be determined. The distortion tells me something is amiss with the AGC system -- incorrect AGC voltage or bad interstage coupling caps putting B+ on the grids.

Received the caps and an ESR tester. So far, so good ... See attached pic.

Good morning friends of the Drake group. I have been given a faulty rx R-4B as a gift. I overhauled the power supply part which was found to be faulty. The radio now turns on receives its internal

I did not find any ‘4427’s. I’ll find the spreadsheet later as I have an appointment to make at the moment. Steve Wedge, W1ES Time flies like an arrow. Fruit flies like a banana. Sent from

The 2n4427 has unique properties, not easily substituted. Jim WA9Z Exline IA Possibly 2N5109 as a viable substitute. Not easily found these days but here’s one source:

That number looks familiar. I’ve been meaning to post my spreadsheet of available transistors that I sorted from a tacklebox full of randomly-mixed parts. I will try and remember to do this shortly.

Thank you Jim for that bit of information. ,I replaced the transistor a few years ago working on it but just got around to working on it again. Regards, Jim [email protected]> wrote:

Probably a good idea if you have questions about something else in this set :-) 73, Steve Wedge, W1ES Time flies like an arrow. Fruit flies like a banana. Sent from [Proton

Our records show having replaced a few of these over the years.? BM and the buffer.? Almost sounds like it qualifies for common failure analysis. The 2n4427 has unique properties, not easily

Yes, can cap was already replaced before I got this radio. He didn't put a new can style in it, he used individual caps. This tread is very long now. The original problem is solved with the baked

Ciao Ho sostituito i vecchi filtri originali nella mia r-4c anni fa, e sia i 500 che i 250 Hz hanno una perdita di circa 6 dB... Ho acquistato la stessa coppia di filtri da Noble Radio... NESSUNA

It is my intent to do so. Steve Wedge, W1ES Time flies like an arrow. Fruit flies like a banana.

AFAIK,? the R4C used a different tap on? (I think) the IF section, to increase the gain when using the CW filters, due to their higher, inherent insertion loss. On a similar note,? years ago, I

Rob wrote: " Note that aligning T-7C that appears in S/N 21,000 and above is critical and should be peaked on the narrowest bandwidth filter." Cool...mine is 26xxx (loaded with your mods btw) so will

Please publish your results.? ?They will be very helpful to the group 73 K1NR

Hi Craig, Any crystal or multiple crystals in a filter can degrade, increasing the insertion loss that can also degrade the passband shape. The original insertion loss spec for all the R-4C filters

If it were me, I might go the mechanical/non-solder approach. ?Using something like a Fahnestock (sp?) clip or other device for the connection. ?Back in the day there were several RF amp tubes that

That works, John.? But, muffler cement is about the same thing and much easier to obtain as any auto parts store has it for sale in toothpick type tubes. Lee, w0vt

I have used something like cast iron stove cement and pretty sure I used regular solder..?? It worked on a 6146 I recall. John K5MO