Davis_R" <WD8JJA@arrl.net> writes:
So it seems. Do you know why or how it doesn't do anything on AM? I
have
looked pretty hard at the schematic, and for the life of me, I can't
figure
out how it gets disabled in the AM mode
-------------
Hi Rick,
I don't know what to tell you there, it would take your sitting down
with some colored pencils and tracing the I.F. signal flow through the
rig both in and out of the entier I.F. chain and into the speech
processor
on paper to find out how the processor is out of circuit during AM
operation.
(more on that in a moment)
Now that you bring it up. Here's an interesting tid bit for you.
I have a really nice FT-101EE.... someone installed a third party
speech processor into the unit apparently years ago. As you are
more then likely are aware. The EE model did not come with the
processor.
The speech process that was installed into my EE was made by
Harry Lemming G3LLL (in the UK.)
The G3LLL processor when turned on gives a considerable boost to the
RECEIVER I.F. signal too......
Yup, that's what I said, the receiver signal is boosted.
My signals on SSB come up considerably when the processor is turned on
using SSB mode. So go figure !! However it's a known fact that the
G3LLL
processor will do this. I read about it in some early Fox Tango
bulletins
from the mid 1970's other people received the same benefits using the
G3LLL
processor board.
I'm in touch with Harry once in a while by E-mail and next time I talk to
him
I will ask him why this is. The Yaesu processor boards are only in
circuit during
transmitt mode when using SSB.
Now that I think about it, here in part could be part of the reason Yaesu
did this.
If that 2.7 Kc (What ever it is-XF-32A) filter is in the I.F. during
receive mode.
The it could possibly present a problem of being too narrow a filter when
switching over to AM mode. Now more then likely you would never turn on
the processor in AM anyway, but just for giggles I turned my G3LLL
processor
on to see what it would do to the receive signal while I was listening to
10 meter AM.
It was pretty darn narrow and completely defeated the purpose of having
had the AM filter installed in the rig in the first palce. Effectively I
would have
been putting an 8 pole SSB filter in my I.F. during AM operation, there
by
narrowing down the I.F. does that all make sence to you?
I thnink it does to me.....hee hee....
Anyway no real benefits to running a processin in AM mode anyway.
Keep in mind, you need to keep the I.C. plate current down to something
like 150 MA when using AM mode.
It's very important you do this. Running the rig at something like 20 or
25
watts output at the very most. If you run it any harder you will be
buying yourself
a new set of 6JS6C finals and they don't come cheap these days.
To be completely honest with you, I don't know all the engineering behind
the
speech processing. I have read up on it a bit, but I really need to look
at the
text again before I can speek on the subject with any confidence.
In my simple lay man's terms, as far as I know there would never be any
benefit running the processor in AM because you already
have a carrier present which then becomes amplitude modulated increasing
the
amplitude of the carrier to it's Peak to Peak value. I can only assume
that
SSB mode the mode is not 100% efficient, such is the case with anything
in this life. (RF amplifiers included)
So the speech processor attempts to bring the SSB signal back to it's
AM equivilent of what you would see had you been running AM or CW
at full power of say 100 watts, there by filling in the valleys inbetween
your syllables when speeking on SSB voice mode.
It is again important to remember that you are running SSB, the 6JS6C
tubes
can take this because they are not running at a CONTINIOUS DUTY CYCLE
ON SSB. Once you go to AM, you are running continously and it's rough
on those tubes. So the RF speech processor will bring up the average
signal
being produced and you will see an increas in your output as well as an
increase in current as shown on the current meter (I.C. position) but you
will
never reach the same level of continous output that you would reach power
wise, say if you were running 150 watts keyed down in C.W.
I hope this makes some sence here because I'm rambling on some.
Sorry.
Maybe another contributor to the forum can enlighten us on the finer
points of speech processing. I think I'm close with my understanding,
but I'm no electrical engineeer.
Stay and touch and feel free to write again anytime.
Regards
Carol Maher
W4CLM
.
----- Original Message -----
From: "Carol L Maher" <w4clm.ham@juno.com>
To: <WD8JJA@arrl.net>
Sent: Tuesday, May 20, 2003 2:08 PM
Subject: Re: FT-101E Speech Processor
> Won't do a thing that I know of on AM Rick.
> Regards
> Carol
>
>
> On Tue, 20 May 2003 11:12:35 -0500 "Davis_R" <WD8JJA@arrl.net> writes:
> > Hi Carol. Thanks for the reply.
> >
> > To be honest, I listen more than transmit. But from what I can tell
> > from
> > the few signal reports and a limited number of on-the-air
> > experiments, I
> > think it does the job well. I QSOed with one guy that said on/off
> > didn't
> > make any difference. I was an S-9 to him. When we finished, another
> > in
> > Texas said I was S-4 and came up about one S unit and the audio was
> > louder.
> > I don't know if there is any reason to turn it OFF in SSB. Of course
> > it
> > needs to be off for PSK31, SSTV, etc. I don't know if it works at
> > all on
> > AM.
> >
> > 73 and God Bless.
> > Rick, WD8JJA.
> >
> > ----- Original Message -----
> > From: "Carol L Maher" <w4clm.ham@juno.com>
> > To: <wd8jja@arrl.net>
> > Cc: <yaesu@contesting.com>
> > Sent: Sunday, May 18, 2003 4:42 PM
> > Subject: FT-101E Speech Processor
> >
> >
> > > Rick, your processor sounds to me like it's operating properly.
> > > How's it working out for you now that you have had a chance to
> > run it a
> > > while?
> > > Regards
> > > Carol
> > > W4CLM
> > >
> >
> >
>
|