[Yaesu] FT-1000D transmit control settings

[Ed Senior]

Hi John -

Some comments below...

----- Original Message ----- 
From: "John Nelson" <john at crew-green.com>
To: <yaesu at contesting.com>
Cc: <yaesu at mailman.qth.net>
Sent: Monday, December 20, 2004 12:57 PM
Subject: [Yaesu] FT-1000D transmit control settings


> My apologies in advance if this question re-visits old ground, but I've
> scoured the Web for information and not found quite what I'm looking for.
>
> In the FT-1000D (as opposed to the later variants) you have controls for
> mic gain, RF power output, processor level and something called 'drive'.
> I'm trying to establish how these should be set up for good-quality audio
> and optimum IMD performance on SSB. I'm also interested in avoiding
> initial 'spikes' of excessive RF, which don't do the linear amplifier much
> good.
>
> I use a Heil HC-5. Following the procedure in the manual, I end up with
> the mic gain at about 9 o'clock and the processor and drive controls at
> about 12 o'clock. My amplifier needs about 50W to drive it to full power,
> so the RF power control is usually at about 2 o'clock.
>
I use CW to make Drive and RF Power settings.  On my unit, I get an
indicated 75W output when the RF Power knob is at 12:00.  (That seems
quite different from yours.)  I also use 12:00 for the Drive control; and
that seems to keep the ALC in range across the bands.

I also use a Heil, and both my Mic gain and Processing are set to 10:45.
I arrived at the Mic and Proc settings via a combination of meter readings
and monitoring my own audio with the Monitor function.  All my audio
reports are good to excellent; but I have no way to check on output spikes
related to ALC transients.

> These settings work fairly well but allow occasional excessive-power
> transients. I can get rid of these by winding the drive back to about 10
> o'clock and advancing the RF power control slightly, but then the
> processor level changes rather markedly. Which doesn't seem to make
> much sense. And despite having thought about it for some time, I'm still
> not really clear about the functional difference between the drive and
> RF power controls.
>
The implication of the function names is that Drive regulates the input
levels to the finals, whereas RF power regulates the output levels.
Perhaps it does that by setting an ALC reference; but I have to admit
that I haven't tried to dope it out from the schematics.

> SM5BSZ shows some very interesting transmit IMD plots for the 1KD
> on his site but it's not very clear to me how he arrives at them. He seems
> to be saying that one should avoid operating in the ALC region at all.
> Is this the case?
>
This would be contrary to the manual instructions, and would almost
certainly reduce the maximum power output.  But if the ultimate in audio
quality is more important than output or "punch," then it is likely that
reducing levels would give you what you want.

> I'd be very interested to hear how you run your FT-1KD and how you think
> these four controls interact. Do you go by the manual? Or have you found a
> better way?
>
Mine is pretty simple-minded, but it seems to work fine:
1.  Set Drive so that ALC stays in range across frequencies and bands.
     (I use CW for this.)
2.  Set Mic gain using Monitor and indicated (peak) Power so that
     full output can be obtained with minimum audible distortion
     (with Processing Off).
3.  Turn Processing On, and adjust Processing gain to produce 5 dB or
     so of indicated compression.  (I like a little extra punch, but don't
     like highly compressed audio.)
4.  Set RF Power to 200W if barefoot, or to level required for desired
     output from linear amp.  (I use CW for this.)

73, Ed, W6LOL


> 73 John
> GW4FRX
>
>