[amsat-bb] Yaesu FT-857D and Doppler

[John]

Hasan,

It's a "design feature". As you said, you've been told correctly. It doesn't
accept CAT commands for changing frequency whilst in TX.

73,
John (M5ET)

-----Original Message-----
From: AMSAT-BB <amsat-bb-bounces at amsat.org> On Behalf Of Hasan al-Basri
Sent: 01 November 2018 13:54
To: amsat-bb at amsat.org
Subject: [amsat-bb] Yaesu FT-857D and Doppler

I have been told that this radio will not accept CAT doppler adjustments
while it is transmitting. I definitely see that it doesn't, but don't know
if I might be doing something wrong.

Here is how it behaves:

If not transmitting, doppler correction works perfectly. As I assert PTT,
doppler adjustment stops and I slide up the band...pretty quickly on high
passes. If I hold the ptt for more than a couple of seconds, I will go right
out of the passband of my 2.2 kHz filter...and of course become
unintelligible.

As soon as I drop PTT, and key the mike again, I'm dead on freq...and as
long as I hold the PTT on, I drift up the band. *It appears the the FT-857D
will not accept CAT commands while PTT is asserted.*

At this point I need to know that there is no real solution to this problem
with this radio. If that's true, I can get pretty good at doing this:

1. Assert PTT and start talking.

2. Grab VFO knob, adjust as I talk to keep sounding good.

3. Drop PTT and begin to listen to other station. (at the drop of PTT,  tx
freq snaps to "proper" place that it couldn't get to when PTT was asserted)

4. My turn to talk: Assert PTT and I'm dead on freq where I belong.

Basically, I'm doing manual uplink adjustment to freq while I'm talking and
letting the CAT adjustment for doppler to take place (to the uplink freq)
while I'm listening.

*If there is a better way to do this, please advise*.

Note, it is not practical to drop PTT quickly enough and often enough to
prevent the problem...I can only speak a couple syllables at best, before I
slide away.

Equipment and Setup:

Rx: SDRPlay RSP2 Sofware Defined Radio with SDR Console v 3.03 providing
Doppler to Rx

Tx: Yaesu FT-857D controlled as External Radio by SDR Console v 3.03
providing doppler correction to the External Radio.

p.s.  I have tried other doppler control programs and they behave the same
way.

Any and all help would be most appreciated, even simply: You are stuck with
the way you are currently doing it.

73, N0AN





Hasan
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