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  1. K

    My friends make fun of me.....

    Like I said before. MY kilowatt transmitter works.
  2. K

    My friends make fun of me.....

    Cigarette smoke preserves radio equipment. Also the owners die sooner. Winner: people who do silent key estate sales. Clean the radio witm ammonia and let it sit around a few months. No more smell.
  3. K

    Filament voltage .. AC/DC?

    Some like the 12AX7 are but it does not complete the cathode to ground circuit as in directly heated tubes.
  4. K

    Filament voltage .. AC/DC?

    AC filaments if directly heated use a centertap on the transformer to complete the cathode circuit. They have extremely tiny amounts of hum. I've heard DC will wear out a filament quicker due to more emission on one side of the filament. Not sure though. Standard practice on most tubes is...
  5. K

    40 Meter QRP AM Schematic, What do you think?

    40 meter AM? Biggest problem will be ssb stations thinking you are a shortwave broadcaster. They usually zero beat them in order to use the frequency. Without a buffer you will have some phase modulation and an "interesting" beat note to say the least. Pipe it through a big amp : )
  6. K

    Cap's Across Diodes on Rectifier Board???

    Caps were necessary years ago. They were not there for rf bypassing. Resistors and caps across diodes will not buy anything you need unless you desire to use ancient diodes. Just put plenty in series for more PIV. Many textbooks show different rectifier configurations and their requirement...
  7. K

    Can this really happen?

    When this is all over please let everyone know who the guy is and when he flys. We could hold the next big keydown competition there and show him the difference between pretend and real RFI.
  8. K

    antenna question about dc grounding

    Maybe I should have written it differently. DC grounding does not make antennas have sharp points. The combination of DC grounding AND sharp points on antennas is known to drain pre-strike charges. Better?
  9. K

    antenna question about dc grounding

    I don't understand the question.
  10. K

    antenna question about dc grounding

    Antennas which are DC grounded and have multiple sharp metal pieces are proven to dissipate pre strike charges. Less chance of getting hit in the first place. What happens during a strike is a different matter. Low inductance bonding of all equipment and grounds is the name of the game there.
  11. K

    antenna question about dc grounding

    I wouldn't rely on any of it.
  12. K


    Sorry to hear of this great loss.
  13. K

    How do I acquire my grandfathers lic?

    There are hundreds of unavailable issued calls out there from those who passed away more than 2 years ago. Callsign renewal lasts 10 years now. Lots are not available yet because nobody goes around policing the call database. There are cases where people find out someone has died and...
  14. K

    speaker swr?

    SWR is the ratio of minimum to maximum voltage or current on a transmission line. Nothing more nothing less. This can be measured fairly easily at audio frequencies as the measurement device will not influence the circuit.
  15. K

    2SC2999 modification questioned

    You sir are correct concerning magic receiver mods. Now you can either ignore the folks who swear this stuff works or argue with them. Lots of snake oil in radio land.
  16. K

    The old mobile tube amps ?Broad Band? Tunning?

    Check out the Central Electronics 200V and see how they did it.
  17. K

    Mic and Mixer question.

    Junk the existing D-104 preamp and build one of the many MPF-102 impedance converters found on the WWW. That will play into a mike mixer very well through the unbalanced input configuration.
  18. K

    How do I acquire my grandfathers lic?

    Look up the rules for vanity callsigns. See what class of license is needed to hold that call. Pass the test for that level of better of callsign. Apply using close relative stipulation. Do not make any info including the callsign available on a radio site. If your grandfather's...
  19. K

    When 10 meters is open, try some FM repeaters

    Fine until Tommy Tubes gets drunk and gets on.
  20. K

    Best way to use the transformer

    None of the description here resembles a center tap.