Tuning SWR for a receiver - was RE: [Scan-DC] on glass antenna mounts

[John Bacon]

If you do get an SWR this is your best bet
http://www.mfjenterprises.com/Product.php?productid=MFJ-269

Covers 1.8 to 170 MHz and 415 to 470 MHz.
It injects a low signal to check the SWR to the exact freq within your
range. 
It's a bit more expensive but easier to use.

JOHN

-----Original Message-----
From: scan-dc-bounces at mailman.qth.net
[mailto:scan-dc-bounces at mailman.qth.net] On Behalf Of Andrew Clegg
Sent: Sunday, May 18, 2008 7:43 AM
To: oldsdoug at hotmail.com; scan-dc at mailman.qth.net
Subject: Re: Tuning SWR for a receiver - was RE: [Scan-DC] on glass antenna
mounts

Hi Doug,

MFJ and others sell SWR meters that can be used to check SWR up through 
about 500 MHz. The meters work on the same principle as what you used for 
CB, but the power that they put out is so low that it falls within the Part 
15 (unlicensed emitter) limit. Those could be used to tune an antenna for a 
particular scanner band.

The ham models of SWR meters that I've seen don't go up to the 800 MHz band,

but I'm sure there are professional models that do.

Andy

----- Original Message ----- 
From: <oldsdoug at hotmail.com>
To: <scan-dc at mailman.qth.net>
Sent: Saturday, May 17, 2008 2:29 PM
Subject: Tuning SWR for a receiver - was RE: [Scan-DC] on glass antenna 
mounts



Hey, that brings up a question:

My theoretical knowledge about antennas and SWR is pretty weak, and I really

haven't messed with anything like that in years, since I was a CB'r in the 
really old days before CB got popular!

At any rate:  If I recall correctly, to set SWR, an SWR meter went in line 
between the transmitter and the antenna.

My question is, is there any way to tune an antenna used for receive-only 
(such as a scanner antenna) using an SWR meter?

Thanks!

Doug

> From: gpmorris at satx.rr.com
> To: scan-dc at mailman.qth.net
> Date: Sat, 17 May 2008 12:30:46 -0500
> Subject: [Scan-DC] on glass antenna mounts
>
> BlankJoel Kahn wrote:
>
> "It doesn't seem to matter if you have the wire pointing up down or 
> sideways
> on that piece."
>
> Joel, I found when installing disguise antennas in VHF, UHF and 800 for
> various LEAs back in my Moto days, that the SWR is lower when the cable 
> feed
> is run 90º to the antenna. It may be less important to follow that when
> using RFRO instead of TX/RX but I suspect you'd see a slight improvement
> over inline.
>
> Regards,
> Glenn
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