[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Re: T adapters and Elk Antennas for HTs?



Pieter,
Good thoughts, but for further amplification, white noise is prevalent in
the output of any solid state Power Amplifier and the diplexer will filter
that out as well. Note: The on redeeming feature of the vacuum tube is
VTamplifiers have no white noise.

Art, KC6UQH
----- Original Message -----
From: "Pieter Ibelings" <sietetrescincoprimo@hotmail.com>
To: <amsat-bb@AMSAT.Org>
Sent: Wednesday, October 20, 2004 2:05 PM
Subject: [amsat-bb] Re: T adapters and Elk Antennas for HTs?


> Using T adapters to connect the two sides of an arrow antenna is not
> recommended. For certain impedances and cable lengths, you could have
> extremely bad SWRs. You could also end up having non optimal patterns and
> polarization. The proper way of connecting two antennas of different bands
> is using a diplex filter.
> There is a way that a diplex filter used with an arrow and an HT can help
> your desense. Antennas can create distortions in their metal to metal
> junctions (even at 5 watts). If you use a diplex filter to combine both
> antennas in an arrow, the distortions created by the 145 MHz transmitter
> will not be able to get back to the radio through the low pass side of the
> diplexer. It is true that the 435 side antenna will capture some of that
> harmonic energy, but the fact that they are 90º spatially will minimize
it.
>
> On the ELK antenna, any distortions produced in the antenna with be
"common
> path distortion" (CPD). There will be no way to filter these because they
> occur in a common path to both the 145 and 435 sides.
>
> Pieter
> ----
> Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> Not an AMSAT member? Join now to support the amateur satellite program!
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home