Fwd: Re: Elecraft group

[Eric-2]

Hi Chen and Pete:

  Hah!  Well, I want to make this as simple and trouble-free as we can.  We
can get as tricky as we want to later.  I suggest a simple pair of crossed
dipoles, with a 90 degree phasing line between them. and some means of
swapping the polarity of one of the dipoles.  (My QST article shows the
simplest way of doing this).  If we limit it to just 15 MHZ, we don't have to
worry about broadbanding anything.

We just need to see if there's a significant difference in signal strength of
WWV as you swap the sense (go from RH circular to LH circular).

Chen, I think YOU will know the implications of this if you DO see a big
difference...but I want to see what other hams scattered across the country
see!

Peter:  Did you see my X and O article in the December QST?  This will give
you a good background on this.

73 es thanks for your interest!


Eric
--
Eric P. Nichols, KL7AJ, NNN0AKA, WD2XSH/27
P.O. Box 56235
North Pole, AK 99705
[phone]
[hidden email]
[hidden email]
[hidden email]
http://ericnichols.net
On Saturday 20 November 2010 10:12:12 am you wrote:

> Hah, as if I have two horizontal dipoles at my disposal :-).
>
> I have two acres at this QTH, but I also have dizziness with height
> (vertigo), so no towers but vertical antennas.
>
> My option is a small receiving antenna, but they are not that nice to
> phase directly.  That is why I contemplated phasing at the IF of SDRs
> that share the same LO.
>
> I have a Comtek PVS 2 for 20m, by the way.  It is not a perfect 90
> degrees when antenna impedances at not perfectly 50 ohms (it uses the
> twisted wire hybrid), but is not that bad (and you can switch between
> +90, -90 and 0 degrees from inside the shack).  I need to check how it
> well works on 30m (I have a TAPR VNA to measure with, not great, but
> usable for this kind of thing).  If I remember from the old IEEE paper
> (and also a QST article from the 50s, I think) the twisted wire hybrid
> is moderately broad.
>
> I'll check some more on that since Tony-the-Softrock-guy has not
> replied to my request at his web site (the email address I have for
> him no longer works).  His web site appears to be inactive for a year
> now.  So some direct phasing, such as the PVS 2.  I can also homebrew
> a twisted wire hybrid easily since it is for receive only -- but will
> need a way to remotely switch it from -90 to +90 degrees.  That way, I
> can fashion it for 30m.
>
> The thing I am not sure about is how well a twisted wire hybrid works
> for highly reactive antennas.  Perhaps it is time to investigate
> hybrids for reactive antennas -- fun tangent to segue to :-).
>
> Vy 73
> Chen
>

-------------------------------------------------------
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html