This has been a hot topic recently! I just scanned an ARRL article
and a section of the test equipment chapter of the RSGB VHF/UHF
Handbook to send to someone else who is interested in making a
146/440MHz SWR monitor, and I just made a couple 100MHz-6GHz detectors
for someone else who is looking at monitoring SWR at 2.5GHz.

Seems to me the simple way for most folk to do it is to make a
microstrip coupler. You can use surface-mount components for the load
and detector and RF decoupling, and they'll work quite well up into
the GHz region, from my experience. As far as RF decoupling goes, you
should be able to do an adequate job on a circuit board...once the
detector turns the RF to DC, just put shunt capacitance to ground and
series inductance in the line. Pick the inductance as you would for
other VHF work: avoid inductors with self-resonances below the freq
of interest.

You probably have already seen the ARRL article I scanned, but if
you'd like the RSGB one, I could send it. But it's almost 4 megabytes
and may take you a while to download if you have a slow connection.

Cheers,
Tom


Uwe Langmesser wrote in message ...
I have been looking at various designs of VHF SWR bridges, mainly from ARRL
sources like old QSTs and such, and I wonder if anybody here has built a
device like that.
For my experience level some of the old descriptions are just a touch to
cryptic or the design calls for parts which I can't locate (small feed thru
caps are one of those items).
I would love to discuss this with a knowledgable builder.

73 Uwe

Take a look at:

http://www.ldgelectronics.com

It's a kit.

Regards

Ralf

--
Vy 73 es 55 de Ralf, DL2MRB
E-Mail:

On Wed, 11 Feb 2004 00:36:05 +0100, Ralf Ballis - DL2MRB
wrote:

Take a look at:

http://www.ldgelectronics.com

It's a kit.

Regards

Ralf

tried some amateur rubbish the other year, but the problem with
amateur constructions is ususally that you cannot make two units which
performs similarly, and it is difficult to tell what decides the
impedance. If somebody have another opinion I'll be pleased to hear,
it is not 1% accuracy I am after, 10% is good enough and that the
readings are successively the same for the same conditions. Put some
info about some simple couplers you can make on my site, you'll find
it with google search for "Bird Model 43 patent description"

73,

On Wed, 11 Feb 2004 00:36:05 +0100, Ralf Ballis - DL2MRB
wrote:

Take a look at:

http://www.ldgelectronics.com

It's a kit.

Regards

Ralf

tried some amateur rubbish the other year, but the problem with
amateur constructions is ususally that you cannot make two units which
performs similarly, and it is difficult to tell what decides the
impedance. If somebody have another opinion I'll be pleased to hear,
it is not 1% accuracy I am after, 10% is good enough and that the
readings are successively the same for the same conditions. Put some
info about some simple couplers you can make on my site, you'll find
it with google search for "Bird Model 43 patent description"

73,

Take a look at:

http://www.ldgelectronics.com

It's a kit.

Regards

Ralf

--
Vy 73 es 55 de Ralf, DL2MRB
E-Mail: