[TowerTalk] SWR Analyzer / BC Interferance

[Earl Morse]

Your mileage is going to vary.  At Field Day everyone notices the RF getting into the analyzer from the other sites as a SSB or CW signal momentarily pegs the analyzer meter.  However, with a constant AM station it might just appear that the SWR is slightly off or that you can't obtain a resonance depending on the amount of RF getting in.  I have a couple of multi KW AM transmitters about a mile or so away and I never gave them a second thought about messing up my MFJ259 but I did end up doing all the calculations to find out how they were mixing to give me a birdie here and there on 160M.  SWR on the antennas turned out ok cuz I measured it with power and an SWR meter.

I think the MFJ filter for BCI is just a notch filter and you have to adjust it for a particular station.  It might not work so good if you have more than one station in near proximitiy.  If your analyzer covers 160M and you are in the shadow of an AM station, especially one in the high end of the band I would expect some effects from it whether you noticed them or not.  Might have to compare between an SWR bridge and the analyzer to see the difference.

I haven't looked at new ones yet but wouldn't mind an analyzer that was a little more immune to RF, have a computer interface so you could export data or use it on the bench as an instrument (sig gen, network analyzer, etc), and be pseudo lab grade (accurate and more stable).  Having the graphical display built in while a perk doesn't seem to be a big deal (especially if you could plug it into a computer) as you usually just rock the frequency between the SWR 2:1 points and note the frequency/bandwidth and center frequency of the resonance when checking an antenna.

Earl
N8SS

--- towertalk-request at contesting.com wrote:

From: towertalk-request at contesting.com
To: towertalk at contesting.com
Subject: TowerTalk Digest, Vol 165, Issue 61
Date: Thu, 15 Sep 2016 15:03:43 -0400

Send TowerTalk mailing list submissions to
	towertalk at contesting.com

To subscribe or unsubscribe via the World Wide Web, visit
	http://lists.contesting.com/mailman/listinfo/towertalk
or, via email, send a message with subject or body 'help' to
	towertalk-request at contesting.com

You can reach the person managing the list at
	towertalk-owner at contesting.com

When replying, please edit your Subject line so it is more specific
than "Re: Contents of TowerTalk digest..."


Today's Topics:

   1. Re: SWR Analyzer / BC Interferance (StellarCAT)
   2. Re: SWR Analyzer / BC Interferance (john at kk9a.com)
   3. Re: SWR Analyzer / BC Interferance (Jim Brown)
   4. Re: SWR Analyzer / BC Interferance (Al Kozakiewicz)
   5. Re: SWR Analyzer / BC Interferance (Joe Subich, W4TV)
   6. Re: SWR Analyzer / BC Interferance (Richard Thorne)


----------------------------------------------------------------------

Sent from my iPhone

> On Sep 15, 2016, at 8:14 AM, Richard Thorne <rthorne at rthorne.net> wrote:
>
> Quick question.
>
> Is the MFJ series of SWR analyzer's the only ones susceptible to BC
> interference?  Any issues with the Comet or RigExpert series?
>
> I know I can get a filter for the MFJ, but I don't need extra things
hanging
> off the device, doesn't make much sense to me.
>
> I'm leaning towards the RigExpert as the feature list appears to be longer
> than the Comet.
>
> Thanks
>
> Rich - N5ZC
>

_______________________________________________



_______________________________________________