[600MRG] IC735 mods...an alternative

[John Langridge]

>Since the target frequency is below 160M, why would harmonics be much of
an issue with the 160M LPF?


Second harmonic of 475 is 950, which is in use in many BC markets...  473's
third harmonic is right around 1420...

Many of us have taken the drive of shame where we activate our stations on
WSPR or CW and still hear our signals on 950 kHz many miles away.  Never a
good thing.  Adding one of the W1VD-designed filters made it where I
couldn't hear myself sitting in my drive way.

73,

John


On Fri, Jan 26, 2018 at 9:32 AM, J Mcvey via 600MRG <600mrg at mailman.qth.net>
wrote:

> Got $9 in the budget?
> https://www.mouser.com/Passive-Components/Frequency-
> Control-Timing-Devices/Oscillators/_/N-7jdfi?P=1z0woad
> just add 3.3 to 5V , a cap and a filter if you like...
>
> Those Ic735 mods mostly seem to extend the PA capability downward in
> frequency.
> Not sure what shorting the transistor in receive section  was about but
> those were my initial impressions.
>
> The LPF might need some tweaking for 630M. I think going all the way down
> to 2200 meters is too much of stretch, though.
> I might try before and after tests with a spectrum analyzer to see what
> happens when I get time to do it.
>
> Since the target frequency is below 160M, why would harmonics be much of
> an issue with the 160M LPF?
> Add a 630M section in series with the 160M LPF?
>
>
> On Friday, January 26, 2018 7:53 AM, N1BUG <paul at n1bug.com> wrote:
>
>
> >> Why ruin a perfectly good radio???
>
> If I'd had a IC-735 around that wasn't being used on HF, I probably
> would have 'ruined' it in a heartbeat. That would have been the most
> cost effective way to get on.
>
> With a little help to keep it within budget I build a really cheap
> transmit converter. But since a good stable 10 MHz oscillator isn't
> happening here for some time, I'm using a signal generator that I
> would prefer not to leave running for so many hours. So even now, if
> I had a 735 that wasn't needed for HF I'd dig into the little
> bugger... ;-)
>
> 73,
> Paul N1BUG
>
> ______________________________________________________________
> 600MRG mailing list
> Home: http://mailman.qth.net/mailman/listinfo/600mrg
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:600MRG at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
>
> ______________________________________________________________
> 600MRG mailing list
> Home: http://mailman.qth.net/mailman/listinfo/600mrg
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:600MRG at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/600mrg/attachments/20180126/1af7b9d1/attachment.html>