Steve, you can purchase excellent quality vac variable caps from Dr Alex
Gavva UR4LL for a very reasonable price
Bob..VK3ZL..
_
Topband Reflector
I am now using twisted pair on my receiving Delta antenna and is less noise
than the coax.
Question: Any one ever tried using light fibers as a near ultimate transmission
line from their receiving antennas?
73
Bruce-K1FZ
www.qsl.net/k1fz/beveragenotes.html
_
Topband Reflector
Why doesn't Rob do us all a favor and sell Idiom Press to a company that
seems to have its act together, such as DX Engineering, Array Solutions
or W4PA (Vibroplex/Spiderbeam USA) ? He's certainly not going to make
any money the way he currently runs the company.
73,
Steve, N2IC
On
Tim,
Good information, but I was thinking of a way for Mr. Average DXer to get
a connection, that is not adding noise, from his on site receiving antenna.
73
Bruce
- Original Message -
From: Shoppa, Tim tsho...@wmata.com
To: Bruce k...@myfairpoint.net
Sent: Thursday, October 24,
I do not know of any analog optical coupling technology that has nearly the
dynamic range of copper.
50dB is considered quite good HF dynamic range for completely sealed analog
optocouplers. Start putting cables and junctions in there and it has to only
get worse.
Tim N3QE
-Original
I use ladder line from the Wireman and from Davis RF. I think the
conductors are copper plated solid steel.
I bought 1/4 thick 2 wide strips of acrylic from McMaster Carr and
made a pair of clamps of 6 long pieces by cutting grooves for the wire
thickness, two holes for ss bolts and one for a
I use twinlead (DX-wire or Wireman) 300 Ohm, less attenuation compaired to
RG58 and small. not much windload.
Doing its job for over 5 years now. Only fixed at the ends.
Kees, PE5T
--
From: Les Kalmus w...@bk-lk.com
Sent: Thursday, October 24,
How long it lasts really depends on how mechanically intuitive we are when
we install the antenna.
Key things are to let the wire float in everything but the end supports, and
make sure things don't cut, flex, or rip the wire apart. Spreading the end
load, if you grip the insulation, is a
I am now using twisted pair on my receiving Delta antenna and is less noise
than the coax.
If you now have less noise with a twisted pair, it only means you had a
significant design or installation issue with your coax someplace in the
system.
73 Tom
_
Topband
While I have tried this myself, you could try black UHMW for your supports on
the middle posts between the ones taking tension. UHMW is Ultra High Molecular
Weight polyethylene. The black stuff holds up outside pretty well. It wouldn't
be hard to make a small support with a bottom and top piece
Um, no... Not really -- you do NOT need modulators and demodulators to use
fiber for *analog* applications. If you want to run your signal over a
commercial transport network you will (to digitize the signal and deal with
framing for SONET, Ethernet etc.). Cable TV systems run their RF over
CATV analog modulation video over fiber has a typical 50dB dynamic range. See
e.g. http://www.emcore.com/wp-content/uploads/Medallion-6000-Series.pdf
Tim N3QE
-Original Message-
From: Bill Wichers [mailto:bi...@waveform.net]
Sent: Thursday, October 24, 2013 12:10 PM
To: Tom W8JI;
- Original Message -
From: Bill Wichers bi...@waveform.net
To: Tom W8JI w...@w8ji.com; Shoppa, Tim tsho...@wmata.com; Bruce
k...@myfairpoint.net; topband@contesting.com
Sent: Thursday, October 24, 2013 12:10 PM
Subject: Re: Topband: Light fiber question
Um, no... Not really -- you
I see your point, since the signal is undergoing a conversion. My thinking was
modulator = baseband to some kind of RF or digital signal, i.e. something very
different from the original signal in terms of content of the waveform. I
wasn't thinking of using a band-limited section of spectrum
I see your point, since the signal is undergoing a conversion. My thinking
was modulator = baseband to some kind of RF or digital signal, i.e.
something very different from the original signal in terms of content of
the waveform. I wasn't thinking of using a band-limited section of spectrum
BTW, Bill, amplitude modulation and mixing are the same process
mathematically. In a mixer we just select one of the sidebands
-depending on whether we are doing up-conversion or down-conversion
mixing. So, in an optical fiber, passing 2 MHz 160m RF, there would be two
sidebands at 2 MHz above and
From Tom
People forget, or don't know, fiber cables require modulators and
demodulators. The modulators and demodulators are not simple, and have
horrible dynamic range compared to a simple piece of coax.
From Bill
The important part would be that you'd need to run a feedback loop with the
Well, might work. Another idea though, check with Fair-Rite - I believe that
they have some cores that wil fit over .405 RG-8, and I know they have lots
that sill fit over RG-58 or RG-8X. If you don't mind removing the
connector, you can just slip a bunch of them over the end of the cable and
use
That would work as well. I used something similar, but with less turns to
precede the 4:1 current balun feeding the drivers on my home brew 5-band
quad.
Charlie, K4OTV
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim
Bennett
Sent: Thursday,
Check this link out. It works flawlessly.
audiosystemsgroup.com/*RFI*-Ham.pdf
On Thu, Oct 24, 2013 at 7:47 PM, Charlie Cunningham
charlie-cunning...@nc.rr.com wrote:
That would work as well. I used something similar, but with less turns to
precede the 4:1 current balun feeding the drivers
What works flawlessly, Randy? The link? J
73,
Charlie, K4OTV
From: Randy Lake [mailto:randyn1...@gmail.com]
Sent: Thursday, October 24, 2013 7:51 PM
To: Charlie Cunningham
Cc: Jim Bennett; g...@ka1j.com; topband@contesting.com
Subject: Re: Topband: Balun question
Check this link
I am sorry! That was not very clear.
The info on chokes worked wonderfully for me on 80m and 160m using the Big
31 snap-ons.
Not only that but lots of good info other than chokes.
Randy
On Thu, Oct 24, 2013 at 7:55 PM, Charlie Cunningham
charlie-cunning...@nc.rr.com wrote:
What “works
Just teasin' you, Randy! J I think the snap-ons would be quick, simple and
very effective and should outlast the antenna, I expect!
From: Randy Lake [mailto:randyn1...@gmail.com]
Sent: Thursday, October 24, 2013 7:58 PM
To: Charlie Cunningham
Cc: Jim Bennett; g...@ka1j.com;
Though this reflector is for 160M I have an 80M question that might
be best asked here. My father W1BML is on an 80 meter net nightly.
His antenna in an inv-V with 40 80 elements though he never uses 40
any more. I needed to fell a couple of trees to remove branches that
were touching his
True!
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI
Sent: Thursday, October 24, 2013 8:41 PM
To: g...@ka1j.com; topband@contesting.com
Subject: Re: Topband: Balun question
Though this reflector is for 160M I have an 80M question that
A W2DU balun, however is another story! Walt knew what he was doing!
73,
Charlie, K4OTV
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI
Sent: Thursday, October 24, 2013 8:41 PM
To: g...@ka1j.com; topband@contesting.com
Subject: Re: Topband:
There are niche applications, called antenna remoting, where photonic and
fiberoptic technologies are used to transmit RF signals from an antenna to a
remote receiver. You can buy commercial systems to do this. I once
designed such a system for a government application to send RF signals from
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