[ICOM] IC-746 (Original) on 60m?

Larry Benko xxw0qe at comcast.net
Mon Dec 22 01:59:31 EST 2008


Mac and others,

Take a look at http://www.bnk.com/w0qe/60m_operation.html which clearly 
explains how to determine whether an opened up (TX frequency wise) radio 
will be happy transmitting on 60m.

On my web page I tried to make it clear how to determine if a radio will 
have problems operating on 60m.  If your radio produces a click at 
5.00MHz the radio uses the 80m low pass output filter for frequencies 
lower than 5.00 MHz and uses the 40m low pass filter for frequencies 
above 5.00MHz.  Since 60m is ABOVE 5.00MHz your radio is using the 40m 
filter and all will be fine. The basic problem occurs if the radio tries 
to use the 80m filter which by 5.3MHz may have significant loss which 
causes the radio to either shutdown on 60m or operate by drawing too 
much current which is hard on the output transistors.

I still feel that telling someone the exact date when a post was made is 
better than reiterating the same thing over and over.  While the 
archives are not searchable by topic and words a post on a given date is 
easy to find.

73, Larry W0QE


73, Larry W0QE


D C *Mac* Macdonald wrote:
> Dick and Larry!
>  
> Please note that this reply is private and not to the Icom mailing list.
> I have been a member of the mail list for quite some time.  That is
> my only knowledge of information.  I hadn't even thought of 60m
> coverage until a friend about 175 miles away emailed me and asked
> if I could meet him on one of those frequencies.
>  
> I cannot save everything that comes across my email that might
> POSSIBLY be needed.  I get over 150 emails a day on about a
> dozen mail lists covering SEVERAL hobbies.
>  
> I have read several files regarding opening up the coverage on my
> IC-746, but none mention whether there is a problem regarding the
> bandpass filters that would preclude such operation.  I have seen
> one article that talks about where the rig switches filters.  Mine gives
> the big relay click at 5 MHz and also 6 MHz.  And that leaves me in
> the dark as to whether the 746 is actually a candidate for 60m use.
>  
> 73 - Mac, K2GKK/5
> Oklahoma City, OK
>
>  
>
> > Date: Sun, 21 Dec 2008 17:48:42 -0800
> > To: icom at mailman.qth.net
> > From: dick at k7vc.com
> > Subject: Re: [ICOM] IC-746 (Original) on 60m?
> >
> > A lot of questions are asked by new members who subscribed to the
> > reflector simply to ask their question. Telling them to search the
> > archives may seem appropriate, but telling them -how- to search the
> > archives would be much more constructive.
> >
> > We are all friends here. Help, don't just chastise.
> >
> > Dick
> >
> > At 04:05 PM 12/21/2008, you wrote:
> > >It is not much of a search since I gave you the date. Anytime there is
> > >a recent thread covering the topic it is reasonable to tell someone 
> what
> > >the date was so they can see all the replies themselves. It seems kind
> > >of foolish is a previous thread had a dozen replies to repeat them all
> > >again.
> > >
> > >73, Larry W0QE
> > >
> > >KI9A at aol.com wrote:
> > >> Wow, are you saying everyone should do a complete search of
> > archives, prior
> > >> to asking a simple question?
> > >>
> > >> 73- Chuck KI9A
> > >>
> > >>
> > >> In a message dated 12/21/2008 5:28:57 P.M. Central Standard Time,
> > >> xxw0qe at comcast.net writes:
> > >>
> > >> This topic was discussed on this reflector on 11/27/2008. A 
> search will
> > >> find it. There is more to it than just clipping a resistor to get 
> wide
> > >> TX capability. The output low pass filter also needs to be
> > >> understood. Look at my post on 11/27/2008.
> > >>
> > >> 73, Larry W0QE
> > >>
> > >> D C *Mac* Macdonald wrote:
> > >>
> > >>> Is this possible, and if so, what mod(s) need to be accomplished?
> > >>>
> > >>> Thanks in advance!
> > >>>
> > >>> 73 - Mac, K2GKK/5
> > >>> Oklahoma City, OK----
>


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