View Single Post
  #2   Report Post  
Old July 1st 10, 09:56 AM posted to rec.radio.amateur.homebrew
raypsi raypsi is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2008
Posts: 242
Default Parasitic Oscillation

.. *Misfortunately a Q of 5 is
not quite low enough to reduce VHF gain enough so that oscillation can not
be sustained *It apparently takes a Q of *2 at 100MHz to achieve
acceptable VHF stability. *One way to decrease Q involves exchanging the
highly-conductive Cu wire for highly-resistive Ni-Cr wire * This simple
change results in a Q of c. 2 at 100MHz as measured on a HP 4191A
Z-analyzer. * *By using *two Ni-Cr *VHF suppressors per 2-500z, Q can be
further reduced to c. 1.5.
- *end

--
Richard L. Measures. 805-386-3734,AG6K,www.somis.org


Hey OM:

When I made a living selling tubes, my fav best method of stopping VHF
parasitic oscillations was when the transconductance went kaput from
the little grid wire overheating and burning out. I made a living off
of parasitics.

sum gr8 articles on your website too OM.

73,
de n8zu.