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fascinating. Never saw that FIREBIRD brand swr meter before, but sure enough, you can find it on facebook and yes, they are apparently meant for far more power than a CB radio can produce.

Allison found a really net section of the antenna free pdf and there really are some gems in there!!! I would caution that with a really short antenna (the quintessential example is a small loop) the losses in the matching system can be much larger than expected (by the unwary) because the radiation resistance may be so small that OHMIC losses are now quite consequential in the matching network/feedline etc. With an antenna of more than say 1/3 wavelngth I think there really isn't much of an issue with reasonable sized conductors etc. But then of course, I'm sure someone can find an exeption to that!! I have a good friend, experienced ham, and he found his "loop" to be about 10dB worse than a full size dipole and some published work has corroborated that.

How does this relate to the uBitx? The losses in some antenna designs can be even larger than the dB difference between a 100 watt rig and the uBitx....putting you REALLY in a QRP situation.

I'm really excited by the work Warren and others are doing with the filters. Great work!

Cheers!
Gordon


________________________________________
From: [email protected] <[email protected]> on behalf of Vince Vielhaber <vev@...>
Sent: Monday, September 10, 2018 2:59 PM
To: [email protected]
Subject: Re: [BITX20] uBitx Antenna #ubitx-help

Right, well this firebird isn't even usable as an swr meter unless you
put about a kilowatt into it. In the FWD, the meter won't go full scale
below about 14 MHz.

Vince.

On 09/10/2018 07:41 AM, iz oos wrote:

I have a cheap CB swr meter (just swr not power meter) and a crossneedle
ham-meter. In the instruction sheet they say it is usable between
1.8-30! They are liers!!!! It works from 1.8 to 50Mhz (yes up to the
6meters band) !!! Very similar reading to the ham meter!!! What a
shame... They don't even know what they sell... hihi... hi


Il 10/set/2018 07:40, "Vince Vielhaber" <vev@...
<mailto:vev@...>> ha scritto:

SWR and Wattmeters made for CB are often worthless in the ham bands,
unless you're only using 10M. I picked up a Firebird SWR/Wattmeter
a while back that was supposed to be good for 1.8-30 MHz. HAR!
That thing won't even read accurately (or even semi-accurately) at
21 MHz and gets progressively worse the lower you go. It barely
responds with almost 1KW going into it at 3.9MHz. Needless to say
it's going back on ebay. It is fairly accurate on 10 meters, so it
probably is on 11 too.

Vince.

On 09/09/2018 03:13 PM, Gordon Gibby wrote:

The only cb ones I have tried on 2 m are the long parallel rod
pick up type, they were quite in accurate

For VHF/UHF I use ham products made for the purpose

Cheers

Gordon kx4z

On Sep 9, 2018, at 13:59, Bill Cromwell
<wrcromwell@... <mailto:wrcromwell@...>> wrote:

Hi,

It might start to be a little shaky on the two meter band.
And maybe will work there too.

73,

Bill KU8H

On 09/09/2018 05:37 AM, gonewiththeego@...
<mailto:gonewiththeego@...> wrote:
I was thinking about an Albrecht SWR 20 which I can see
that is used
only for CB. Do you think it should work for 20/40m band ?


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Michigan VHF Corp.

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Michigan VHF Corp.