[ICOM] ICOM 718 SWR meter

[D C *Mac* Macdonald]

AND, I would certainly NOT trust the SWR
indication on an MFJ analyzer. Look for a
REAL power meter such as a Drake W-4 or a
Bird 43. Some of the more recent higher cost
wattmeters from Asia have gotten a lot better
and probably so for even the MFJ wattmeters.
 
Just my personal opinion. It's worth whatever
you have paid for it.

* * * * * * * * * * *
* 73 - Mac, K2GKK/5 *
* (Since 30 Nov 53) *
* Oklahoma City, OK *
* USAF, Ret (61-81) *
* * * * * * * * * * *

 
 

> Date: Sat, 26 Feb 2011 17:13:38 -0800
> From: gfiber at comcast.net
> To: icom at mailman.qth.net
> Subject: Re: [ICOM] ICOM 718 SWR meter
> 
> Do you have or access to a good known dummy load? Something to take the 
> antenna reactance out of the picture?
> i can tell you what ever the SWR meter reads on the IC-718 is also going 
> to be the controlling factor so far as power out is concerned.
> Could be an SWR adjustment problem or some other issue on the IC-718.
> I generally like to get to a known starting point like a good flat dummy 
> load.
> 
> Anyway my opinion.
> 
> Gary K8IZ
> .
> 
> On 2/26/2011 4:32 PM, Patrick Schwarz - KB8RTZ wrote:
> > Curious if anyone else has checked the SWR meter built into the IC-718
> > with the SWR meter of an antenna analyzer such as the MFJ-269?
> >
> > Here is the setup:
> > Antenna - Hustler 6BTV
> > Analyzer - MFJ-269
> >
> > Process of tuning the antenna prior to purchasing the antenna analyzer:
> >
> > Connected a 25 foot feedline (RG8U) between the antenna and transmitter.
> > Per the antenna manual, tuned the antenna on 10m, 15m, and 20m. 30m on
> > down did not tune well or at all. Ground radials helped, but not enough
> > below 30m. Came to the conclusion that my tuning skills left a lot to be
> > desired so invested in an analyzer.
> >
> > Process of tuning the antenna with the antenna analyzer:
> >
> > First, reset the trap lengths to factory lengths, then overall tube
> > lengths to suggested starting lengths using ground radials. Connected a
> > 9 foot feedline (LMR-240) between the antenna and analyzer, manually
> > tuned the antenna per the manual. Disconnected the analyzer and tuning
> > feedline from the antenna. Reconnected the transmitter feedline (this
> > time a 75 foot feedline (RG8U)).
> >
> > Checked the SWR at the transmitter feedpoint with the analyzer. The
> > results at the antenna with the tuning feedline and at the transmitter
> > feedpoint were comparable. Disconnected the analyzer and reconnected the
> > transmitter. The SWR meter built into the IC-718 measured relatively
> > close results on 10m and 15m. The SWR on 20m was a little higher than
> > measured by the analyzer, higher yet on 30m and 40m, and worse yet on
> > 75/80m (granted, 75m is not fully tuned yet).
> >
> > Seems as though one or the other is incorrect. The SWR at the antenna on
> > say 7178KHz on the MFJ reads 1.6. The SWR at the transmitter feedpoint
> > using the MFJ reads 1.6. The Icom SWR meter reads 2.1 or so requiring a
> > little tuning.
> >
> > Has anyone else noticed these types of results?
> >
> > Thanks,
> >
> > Patrick...KB8RTZ...
> > ----
> > Your Moderator: Dick Flanagan K7VC: icom-owner at mailman.qth.net
> > Icom Users Net: Sundays, 1700Z, 14.316 MHz
> > Icom FAQ: http://www.qsl.net/icom/
> > To support QSL/QTH.net: http://www.qsl.net/donate.html
> >
> 
> 
> -- 
> Gary Fiber K8IZ
> GROL PG-19-6691 with shipboard radar endorsement
> Washington State resident
> 
> ----
> Your Moderator: Dick Flanagan K7VC: icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/
> To support QSL/QTH.net: http://www.qsl.net/donate.html