Home |
Search |
Today's Posts |
|
#1
![]() |
|||
|
|||
![]()
Dave Platt wrote:
... or a link-coupled tuner, which works just fine without a balun How efficient is link-coupling? I have an old Sunair PN-099400 auto-tuner that uses motor- driven variable-link coupling. Too bad it runs on 28 vdc. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#2
![]() |
|||
|
|||
![]()
... or a link-coupled tuner, which works just fine without a balun
How efficient is link-coupling? I have an old Sunair PN-099400 auto-tuner that uses motor- driven variable-link coupling. Too bad it runs on 28 vdc. I'm not sure that there's any single answer to that question. Comments on eHam.net from owners of the old Johnson (or Nye) Matchbox link-coupled tuner seem to suggest that it's capable of operating with low losses - significantly lower than are achieved by some of the unbalanced T-configuration tuners mentioned. I suspect that the efficiency depends very much on the design and implementation of the tuner (e.g. air-core coils vs. a toroidal design, size of core, degree of coupling between the tank and the link, wire gauge) and on the specific impedance being matched. Based on what I've read about Z-match tuner design, it seems that close coupling across the inductive link helps boost the efficiency. However, the close inductive coupling tends to come with an increased amount of capacitive coupling, and this can apparently affect the output balance for the worse in some cases. I suspect (but don't know for sure) that link-coupled designs which use a fixed-position, tightly-coupled link (e.g. an air-wound or toroid-core Z-match) may be more efficient than those which use a "swinging" link with variable coupling. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Inverted ground plane antenna: compared with normal GP and low dipole. | Antenna | |||
FS: Emtech ZM-1 QRP antenna tuner | Swap | |||
FS: Emtech ZM-1 Z-Match QRP antenna tuner | Swap | |||
Mobile Ant L match ? | Antenna | |||
QST Article: An Easy to Build, Dual-Band Collinear Antenna | Antenna |