Loading... |
Reply to author |
Edit post |
Move post |
Delete this post |
Delete this post and replies |
Change post date |
Print post |
Permalink |
Raw mail |
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
8 posts
|
Hi group!
I have just finished the alignments and tests (part II) in my (second) K2-project. Sofar all resistance checks are ok, and the results of the alignment and tests have also been ok. Except for one thing: I think that the AGC in the radio behaves rather strangely. It's pretty nervous in the "Fast" position and switching to slow makes it a little bit better, but not perfect. I have also noticed a "chuffing" or "clicking" sound in my heaphones while tuning the radio aound on 40 metres. This sound (which indeed is very difficult to describe) corresponds with the change of digits on the display (regardless of tuning rate) and is very significant with the appearance of a strong signal. Tuning the BC-band above 7100 KHz is very annoying. The behaviour disappears when the antenna is disconnected, but occours again when connecting a signal generator or other RF-source to the antenna jack. Measuring the AGC-treashold voltage on pin 5 of U2 (control board) gives a range from 2.65-3.74 volts when adjusting R1 from counter-clockwise to clockwise. The recommended voltage is 3.80 volts, which I never reach. I've checked the control board very carefully, looking for solder bridges, cold solderings, incorrect components etc, but everything seems to be fine. I've even re-heated all solder joints on the control board without success. Any ideas, anyone? Regards, Hans, LA2MOA K2 #6341 - unfinished _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Loading... |
Reply to author |
Edit post |
Move post |
Delete this post |
Delete this post and replies |
Change post date |
Print post |
Permalink |
Raw mail |
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
524 posts
|
wrote:
> Measuring the AGC-treashold voltage on pin 5 of U2 (control board) gives a > range from 2.65-3.74 volts when adjusting R1 from counter-clockwise to This is normal, 3.8 is only achievable if all components have nominal values (and may actually not even be achievable then). It might be worth checking the 8V regulator voltage, though, as one person with a, bigger, problem with the AGC reference had a regulator that was out of spec. -- David Woolley Emails are not formal business letters, whatever businesses may want. RFC1855 says there should be an address here, but, in a world of spam, that is no longer good advice, as archive address hiding may not work. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Free forum by Nabble | Edit this page |