Home |
Search |
Today's Posts |
#9
![]() |
|||
|
|||
![]()
John Smith wrote:
I wish an indication of SWR which is cheap, uses fewest parts possible, and has the possibility of "automatic operation" and one can be placed on each and every antenna I am playing with (or anything else, maybe one on the bird fountain! grin)... Got just the device for you on page 520 of "The radio amateur's handbook", 1957 by the ARRL. It's called the "twin-lamp" and consists of a piece of 300 ohm twinlead and two flashlight bulbs. I used one in 1957 on my all-band off-center-fed dipole. I ran 40 watts on 11m in those days. :-) You might want to take a look at another type of design for SWR meters. There is one that uses a short piece of slotted line with two parallel conductors that separate the forward and reflected components without phasor addition/subtraction. Here's a schematic of the Heathkit HM-11 SWR meter. http://www.qsl.net/kb7rgg/heath/sche...chema_hm11.gif Note the low component count. The only tricky part is the slotted line but that is a mechanical problem, not an electronics problem. Resistors R1 and R2 attenuate one wave in one direction leaving the other wave in the other direction to be rectified by d1 and d2. -- 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 =---- |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
FS: MFJ 941D Antenna Tuner + MFJ 204B Antenna Bridge + MFJ 202B Noise Bridge | Shortwave | |||
FS: MFJ 941D Antenna Tuner + MFJ 204B Antenna Bridge + MFJ 202B Noise Bridge | Swap | |||
Bridge Megger Tester. Series 2. 500 Volt. | Boatanchors | |||
FS: E.F. Johnson Phone Patch and SWR Bridge, Gonset CPO | Equipment | |||
FS Tennatest RF Noise Bridge 1-150 MHz | Swap |