[Elecraft] SWR Readings:Differences

[Wes (N7WS)]

Stephen,

Thanks for your note.

If hams would think of mismatch in terms of return loss and coupler directivity 
then they might be less surprised at the variability of SWR measurements between 
different 'instruments', such as the built-in SWR measurement circuits within 
our transmitters/amplifiers.

This is an old discussion.  See: 
http://marc.info/?l=elecraft&m=125734496911585&w=2  and: 
https://www.mail-archive.com/elecraft@mailman.qth.net/msg76426.html

Wes  N7WS


On 9/3/2014 2:35 PM, Stephen Prior wrote:
> Wes,
>
> As someone involved in the design and manufacture of couplers for VSWR
> measurement for the aviation industry (admittedly some 30 odd years ago!),
> I would say that you are 100% correct, although I suspect that in amateur
> gear number 4 in your list is probably the biggest culprit of all.  We had
> people on the production tweaking bridges to maximise directivity and it
> was a job that required some skill, e.g. bending leads of matched zero bias
> Schottky diodes until the spec was achieved - admittedly this was in the
> days before the large scale adoption of lead-less components, which must
> have made things a bit easier.
>
> 73 Stephen G4SJP
>
>