Menu

VSWR doesn't matter?

Search this Thread

Prev

Previous Post

Next Post

Next

#15

Report Post

Old

March 12th 07, 11:00 AM posted to sci.electronics.design,sci.electronics.basics,rec.radio.amateur.antenna

Jan Panteltje Jan Panteltje is offline

Jan Panteltje is offline

external usenet poster

First recorded activity by RadioBanter: Jul 2006

Posts: 54

Default

VSWR doesn't matter?

On a sunny day (Mon, 12 Mar 2007 07:36:25 +0000 (UTC)) it happened
(Don Klipstein) wrote in
:

snipped good stuff

Not only is increased output stage heating possible and maybe fairly
likely, high VSWR also causes a high chance of the output stage seeing a
partially reactive load. RF bipolar transistors often do not like those
due to increased need to dissipate power with higher voltage drop. As I
said above, RF bipolar transistors are likely to really dislike
simultaneous higher voltage drop and higher power dissipation.

- Don Klipstein )

All true.
Also normally, there is a pi type filter (to prevent harmonics), between
amplifier and antenna.
This filter _WILL_ match the antenna to the output impedance of the
transmitter, so _even_ if the transmitter output impedance is very
very low (low voltage high current output stage for example), the reflected
power will be nicely converted to match the transmitter, and heat up the
output amp, with its possible destruction as result.

Reply With Quote

Reply With Quote

Thread Tools	Search this Thread
Show Printable Version	Search this Thread: Advanced Search
Display Modes
Switch to Linear Mode Switch to Hybrid Mode Threaded Mode

Posting Rules
Smilies are On [IMG] code is On HTML code is Off Trackbacks are On Pingbacks are On Refbacks are On

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Caculating VSWR from rho and rho from VSWR	Owen	Antenna	69	June 27th 05 01:53 PM
Does it matter about packing?	Nc183d	Boatanchors	12	September 17th 04 08:41 PM
VSWR Question	Mike Coslo	Antenna	6	August 14th 04 04:56 AM
VSWR Fundamentals	Coax Length Police	CB	0	January 25th 04 10:48 PM
WTB: V-UHF WATTMETER/ VSWR	AL GOSS	Swap	0	November 5th 03 03:12 PM

All times are GMT +1. The time now is 02:54 AM.

About Us

"It's about Radio"

Contact Us RadioBanter forum home Privacy Statement

Copyright © 2017