[R-390] Frequency meter

[David Wise]

I browsed all of the links below, and none of these
inputs all three oscillators, although some have a
"BFO" input which might be usable.  In my opinion,
if you want an outboard readout, the AADE DFD3 is
the ticket. It stores up to 32 separate frequency offsets.
Downside: You have to turn two band switches instead of one.

73,
Dave Wise

> -----Original Message-----
> From: Michael Murphy [mailto:mjmurphy45 at comcast.net]
> Sent: Wednesday, September 01, 2004 4:00 PM
> To: Bob Camp; Charles B; R-390 HF Receiver List
> Subject: Re: [R-390] Frequency meter
> 
> 
> Here are a few links. The DFD series is popular.  MM WB2UID
> 
> http://www.aade.com/dfd.htm#prices
> 
> http://www.eham.net/reviews/detail/1457
> 
> http://www.ohr.com/dd1.htm
> 
> http://www.radioadv.com/ham_radio_equipment/FreqMC/A2.htm
> 
> http://www.qsl.net/k5dkz/r4digital.html
> 
> http://www.circuitsonweb.com/resources/Projects/fc50.html
> 
> http://www.aade.com/Applic~1.htm
> 
> 
> ----- Original Message -----
> From: "Bob Camp" <ham at cq.nu>
> To: "Charles B" <ka4prf at us-it.net>; "R-390 HF Receiver List"
> <r-390 at mailman.qth.net>
> Sent: Wednesday, September 01, 2004 6:22 PM
> Subject: Re: [R-390] Frequency meter
> 
> 
> > Hi
> >
> > As the other posts have mentioned it's not a simple thing.
> >
> > A lot depends on how accurate you want to get. RTTY and SSB 
> are the two
> > things that most people would like to tune accurately. With AM the
> > bandwidth of the filters makes a 10 or 100 cycle error a lot less
> > important.
> >
> > If you are going to tool up to do a full readout for SSB or 
> you would
> > need to measure:
> >
> > 1) The first crystal oscillator
> > 2) The second crystal oscillator
> > 3) The VFO
> > 4) The PTO
> >
> > The digital stuff to do that isn't terribly expensive these 
> days, but
> > it does make noise.
> >
> > Once you had all the frequencies measured then oddly enough 
> you would
> > have to know what band you are set to. It turns out that 
> several of the
> > crystals are used for more than one band so there is no direct and
> > simple way to guess the band in every case.
> >
> > That all sounds like a lot of work and I'm lazy. If I was 
> going to do
> > it I'd fake it:
> >
> > No matter what you need some way to track the band switch. 
> Say we slave
> > a pot to the shaft and measure the resistance.
> >
> > The 17 MHz ovenized crystal isn't going to drift much I would simply
> > measure it's frequency with a bench counter and store the result
> > somewhere.
> >
> > The same thing is true to a lesser extent for the crystals in the
> > crystal deck. They do drift but maybe by sixty cycles. I would just
> > measure them and store their frequency as well.
> >
> > That gets us to the BFO and the PTO.
> >
> > There is an old military mod that puts a multi turn gear drive and
> > readout on the BFO shaft. The net result is the ability to reset the
> > BFO very accurately. If you can lock down the BFO shaft fairly well
> > (maybe mechanical detents) you can get around reading the BFO.
> >
> > All that's left is the PTO. You can either count it's 
> frequency or try
> > the slave a pot to the shaft trick.
> >
> > The cute thing about doing it al with pots would be that 
> you have no RF
> > counters at all. You are dependent on the radio not 
> drifting but that's
> > what the 390 is known for.
> >
> > Definitely a bit far from the "well enough alone" zone thought ....
> >
> > Take Care!
> >
> > Bob Camp
> > KB8TQ
> >
> >
> >
> > On Sep 1, 2004, at 9:37 AM, Charles B wrote:
> >
> > >
> > > Is there any place inside the R-390A where a frequency meter can
> > > attached to get a frequency reading?
> > >
> > > Chuck
> > >
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