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I went through the tune up procedure and everything looked good until I got to the last step and the plate current never goes above .1 on the plate meter. I have set the bias with the PS per the

On Fri, 15 Mar 2024 14:57:51 -0700 "Lyndon VE7TFX" <lyndon@...> wrote: When reading the voltage charts in tube radio manuals, the numbers you measure with your DMM likely won't line up. That's because

I sort of already mentioned that in message #76705. :D "n4buq" <n4buq@...> wrote: -- 73 -Jim NU0C

It'll come up eventually, but what also separates a typical VTVM from a DMM is the analog meter movement It's hard to beat that when tweaking a tuned circuit. I love my HP-410Bs and HP-410Cs. Barry -

A DMM works fine if you are measuring pure DC or very low frequency AC as in a power supply. Where you get into trouble is if there is any RF present. The same applies to a scope probe, whether or

Howdy folks! I’m in need of a front panel for a Drake 2BQ. Mine has a fair amount of rust on it and has had since I bought it at Belton many years ago Anyone have a parts unit they will sell me the

And this is why you want to be aware of Heathkit VTVMs in particular, and maybe others, where hobbyists who thought they were smarter than the engineers thought it was a cool idea to move the 1M

That's the best answer and explanation so far.? What separates a VTVM from a DMM, both of which may have the same specified input Z...is the isolating tip resistor.? When taking measurements at

If measuring the grid of a tube , especially one used as an oscillator you often need a meter with a resistor at the end of a probe.? That is why most of the old VTVMs have a 1 meg ohm resistor at

"Lyndon VE7TFX" <lyndon@...> wrote: Appreciate the feedback.? I didn't expect the voltages/resistances to be identical, and yes I went through the entire process out of sheer curiosity and for

100 kHz Crystals used in Crystal calibrators are available (new and used) from various sources. The HC-13 crystal holder size use to cost ~ $13.00 each , BUT with the closure of ICM in Oklahoma City a

*** Or just download them for free: https://www.worldradiohistory.com/Popular-Electronics-Guide.htm - Jerry, KF6VB

I am working on restoring a Drake 1A and the calibrator doesn’t oscillate. ? ?I tested it a simple crystal tester circuit and confirmed that it does not oscillate. So will baking it worth a try?

Fifth Edition is here. https://www.worldradiohistory.com/BOOKSHELF-ARH/Technology/Technology-Radio/Elements-Of-Radio-5th-Edition-Abraham-Marcus.pdf 1947 edition.

I came in to ham radio toward the end of the vacuum tube era, but they had stopped teaching tube theory by the time I got to engineering school.? I remember asking a professor once about tubes, and

Many years ago, when I was a kid, I found a hardcover book titled, "Elements of Radio" by Marcus and it was dated back in the 1950's as I recall. It took the reader from the very beginning of radio up

Mark makes good points in his warnings. After spending decades as a broadcast engineer working with plate voltages between 7 and 12 KV please also follow this advice. Remove any watches, rings,

One hand... Good advice... I was getting ready to post the same precaution. When I started working on vacuum tube electronics, I was trained to keep one hand in my back pocket. That makes it somewhat

I have a Drake AA-10 Two Meter Power Amp. It takes 1 to 1.8 watts input and produces 10 watts output. Guaranteed to work. $20 plus shipping. Gary W0DVN

Gus, your 75m crystal may be bad. Are you using the transmitter or the receiver to control the frequency. Peaking between 80 and 40 with the bandswitch on 80 is peaking the carrier oscillator at 5595.