Sounds like a great use for a remote tuner. (sure wish Elecraft would
develop one). I have an LDG Remote Tuner for tuning a 44' doublet in
the attic of my town home. Works great. 40 through 10 with acceptable
SWR. (unfortunately for me the noise floor isn't a floor - it's a
skyscraper).
Doug -- K0DXV
On 9/28/2015 6:24 PM, Byron Servies wrote:
Sorry, I should have said "none" instead of "1:1". You don't appear to need it.
I also have a very compromised installation, but better now than a
dipole. And, yes, a tidy installation does us a shocking amount of
coax!
Good luck,
73, Byron N6NUL
On Mon, Sep 28, 2015 at 5:02 PM, Byron Servies <[email protected]> wrote:
On Mon, Sep 28, 2015 at 4:37 PM, Douglas Hagerman
<[email protected]> wrote:
I have a space-limited dipole for 20 meters with drooping ends. The KAT-1 tuner
will tune it. What I want to know is whether to use a 4:1 or 1:1 balun, or no
balun,
at the antenna.
Are you feeding the antenna with coax or ladder line?
Even a low dipole will have a feed point impedance of roughly 75 ohm,
so 1:1 would be fine with coax. You may want to consider a current
choke at the feed point, but that's up to you.
With 450 or 300 ohm ladder line, a 4:1 would be more appropriate to
match the feedline to the expected impedance of the K1 input.
If the tuner reports 24 “x10” pF, is that 240 pF or 2.4 pF? A straight reading
suggests that it’s 2.4 pF, but I don’t see how the tuner circuit can provide so
little capacitance. But C4 (82 pF) plus C5 (150 pF) gives 232 pF which could
240 pF if you include some parasitic capacitance, maybe?
Xc = 1/(2 * pi * 14 x 10^6 * 240 x 10^-12) ~~ 47.
So, the tuner thinks it is seeing roughly 50 + j47 and needs -47 of
capacitance to balance it out, right? I'd go with the 1:1.
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
