Garey Barrell <[EMAIL PROTECTED]> made an utterance to the drakelist gang ---------------------------------------------------------------------- Jay -
The only problem is that tube substitution charts are ONLY pertinent for the tube's _designed_ use. In this case, as an amplifier at 15 kilohertz, which has little or no relevance at 28 MHz....
Aside from considerably different Plate Resistance (2.5 times lower) and Interelectrode capacitances of 50 to 600% HIGHER, the 'KM probably works pretty good at 15 kHz. Useless at 28 MHz.
Add to this that the GJ sells for about $7 (or $0.50 during the AES "closeout" a few years ago), the KM is $12 and the JB is $20.
Bottom line, if you are one who keys the transmitter, then looks for the manual to tune it up, then looks for your glasses to read the manual, then checks to be sure the right antenna (if any!) is connected and THEN dips the plate current, you need another transmitter! Perhaps a 4-400 with 350V on the plate!
With careful tuning (read KEEP the plate current DIPPED), a set of finals will last for years. I have T-4XBs with finals that are ten years old, used almost daily, that still have full output.
73, Garey - K4OAH Atlanta Drake C-Line Service Manual <http://www.k4oah.com> [EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] made an utterance to the drakelist gang ---------------------------------------------------------------------- The following is listed as substitutes for the 6JB6: 6KM6 73, Jay/AF2C
---------------------------------------------------------------------- Submissions: [email protected] Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net ----------------------------------------------------------------------
