On Tue, 20 Jul 2004 12:08:34 -0700, Tim Wescott
wrote:


Perhaps if the knobs were relabeled "TX" and "Antenna", and the plate
current meter was relabeled "reflected power"?

Can't really remember. Last time I had to assist it was Rohde&Schwartz
10kW 88.8MHz FM broadcast transmitter, and the colleague could hardly
achieve 1kW output, hi. Another ham worked at another medium wave
broadcast station in the summer 1960, and mentioned on an occasion
that "they had no idea how to tune a transmitter", they had some
different transmitters, incl. an old Marconi 10kW TX from 1933.

I see nothing wrong in principal with wanting to build a no-tune tube
transmitter, although it may be more work than building a
microprocessor-controlled transmitter tuner, and you may run into
insurmountable output-capacitance problems.

Well, I see 100pF output capacitance to cause some troubles on 450 ohm

Another problem is that all plate connections to a common point must
be measured to the same length. I am told this is really a problem,
even for a longwave transmitter, the reference transmitter operated on
360kHz as a console radio station, see my page
http://home.online.no/~la8ak/k56.htm

73, Jan-Martin

---
J. M. Noeding, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/c.htm

impedance for 100pf on 14MHz is -j114, perhaps not so good in a 450ohm
circuit

see http://www.noding.com/la8ak/12345/n12.htm for broadband techniques
with ferrite transformers, and you could always read W2FMI's book
"Transmission Line transformers", but I wouldn't use transmission line
transformers myself

73
jm
---
J. M. Noeding, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/c.htm