The AM Forum
June 18, 2024, 06:32:35 PM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   Help Calendar Links Staff List Gallery Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: Heathkit DX-100 HELP  (Read 4052 times)
0 Members and 1 Guest are viewing this topic.
n8yhy
Guest
« on: June 25, 2005, 02:58:37 PM »

I finally got my DX-100 up and running a few days ago and made my first contact with it on 75M phone..The rig was playing great and had great forward modulations, Towards the end of my QSO it started backward modulating so i ended my qso quickly..I took the rig apart and began looking things over..When i first turned the rig on i noticed that the 12BY7A Driver Tube by the Mic Plug began to glowing a Nice Blue and after a few moments the plates in the tube began to glow red,This happens with the rig turned on Idling not being used. I measured the voltage on Pin 8 of the 12BY7A and it was up around 405 volts which i believe is way to high.I plugged the mic in and there does'nt seem to be any audio now but there does seem to be some type of osculating going on when i turn the audio gain up..Its like its pulsating..Any one ever had or heard of this problem? I did check a few of the componets around the 12BY7A socked like the caps and resistors and they seem to be fine..Please if any one knows any thing about this type of problem please Email me at n8yhy@sbcglobal.net and let me know your thoughts as i would love to get the DX-100 back on the air...thanks chris N8YHY
Logged
Ed - N3LHB
Contributing
Member
*
Offline Offline

Posts: 353


« Reply #1 on: June 30, 2005, 11:08:51 PM »

Check the 560 ohm cathode resistor on the 12by7, I found that mine went way out of limits causing the 12by7 to glow a very nice orange.... If that doesn't help, let me know, there are some other common problems in the dixie 100...
Logged
WA1HZK
Member

Offline Offline

Posts: 1104


WWW
« Reply #2 on: July 15, 2005, 12:48:54 PM »

http://www.criticalradio.com/833%20Rig%20Project/Web%20Pages/Text%20Article.htm

PS
While it's open, replace the Coupling cap from the driver plate to the final grids. Cheapo part & when it shorts it kinda overdrives the finals -POOF_.
Logged

AM is Not A Hobby - It's a "Way of Life"!
Timmy, Sometime in 2007 on a Mountain Far Away..
www.criticalradio.com
www.criticalbattery.com
www.criticaltowers.com
www.criticalresponder.com
Official Registered "Old Buzzard"
wa2zdy
Guest
« Reply #3 on: July 15, 2005, 06:29:14 PM »

Wow, outstanding work on that DX100 driven rock crusher!  If you can't have a BC rig in the shack, that thing is just as impressive.
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
 AMfone 2001-2015
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Page created in 0.05 seconds with 18 queries.