LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #3   Report Post  
Old May 24th 07, 11:19 AM posted to rec.radio.amateur.homebrew
external usenet poster
 
First recorded activity by RadioBanter: Aug 2006
Posts: 47
Default Self Osc Problem

Hi Jack,

See if you can find a project called "A 75 to 120 Watt CW transmitter"
in any of your ARRL manuals, (1973 ?).

Z1 is the APC, RFC4 is the anode RFC, there is a 10R grid stopper on
G1 (pin 5), Decoupling abounds (including the heaters), band switch
shorts unused turns of the output inductor, top chassis shows anode
wiring only, bottom chassis shows grid and drive electronics.

I haven't read the whole article yet, but it seems like a well
designed beastie and a good starting point.

Keep a change of fresh underwear next to the rubber gloves

Regards,

Mark


On May 24, 12:26 pm, Jack Schmidling wrote:
MarkAren wrote:
Grid stoppers: A low value resistor (100 ohms) attached directly
between G2 and the screen supply to reduce the incidental Q of
circuit.


OK but the supply is a 12K resistor from the plate supply. Guess I
don't see what a 100 in series with this would do.

Same applies to G1.


Where does that go? There is a 47K grid leak going through the meter to
ground and a coupling cap from the driver.

So what is this grid stopper supposed to do?

APC - Anti Parasitic Choke.


Roger. The A caused a brain cramp. I have one in there.

Get a 1960s copy of the ARRL handbook and read up on HF amplifier
construction techniques. There has been plenty written.


I have 49, 57, 61 and 73 one of which I take to bed with me every night.

js

--
PHOTO OF THE WEEK:http://schmidling.com/pow.htm
Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silverhttp://schmidling.com



 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
pro-93 problem Andre Scanner 1 September 13th 05 02:08 AM
ADI AR-147 PROBLEM Scott Equipment 1 August 20th 05 06:15 AM
Haynie admits to problem, alzheimers victims respond with, "What problem?" John Smith Policy 111 June 23rd 05 02:55 AM
BPL might not be such a problem after all lsmyer Shortwave 0 October 23rd 04 08:48 PM
ft-980 problem... WB2JKX Equipment 3 July 15th 03 12:01 AM


All times are GMT +1. The time now is 07:53 PM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017