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Re: Anyone FT-847 and 56002EVM/RI?



In a message dated 2/14/00 8:53:58 PM Eastern Standard Time, 
ne1h@ne1h.dyndns.org writes:

> I'm about ready to start hooking up data related stuff for my sat station.
>  Before I do, I figured I'd see if anyone is using this setup.
>  Yaesu 847 and the 56002EVM/RI?
>  Any hookup related issues, any tricks, etc?

Hi Alan,

Just a couple of tips...........

You'll find that the stock TAPR DSP56002EVM/RI doesn't quite have enough 
output drive to get 3 KHz deviation at 9k6. 1k2 transmit is fine as is 
receive at both speeds. On my EVM/RI I removed/jumpered the 1K output pot for 
radio #1. I'm using Doug Braun's 9k6 code and have set my 9k6 modem as 
follows for transmit:
Under user controllable parameters in g3ruh.asm
OLevel  set 0.90        ; output signal level (in rms volts)
With this settings I'm getting ~2.8KHz transmit deviation. As you probably 
know, 3 KHz is the recommended high limit.

For receive, I set it this way:
Under user controllable parameters in g3ruh.asm
RxGain  set     9.0        ; Codec input gain in dB, set to match radio.

Doug provided a neat piece of code called scope9600.lod Use this with Spy to 
check input level. Scope9600 has the same gain structure as g3ruh.asm

I don't know if you'll be automating the tuning of the FT-847, but I've found 
my radio likes to see the frequency set slightly low. In other words if you 
monitor the FT-847 DISC when in SAT mode (set menu #34 to DISC), the 
indicator will be a little left of center. I see slightly better throughput 
on receive when I set the receive frequency this way. FYI, I'm using Uni_Trac 
with WiSP for freq/tracking control.

Don't forget to set the radio data output speed via menu #23 Pkt Rate to 9600 
when using the 9k6 birds. Good luck and hope to see you on the digital sats 
soon.

73,
Mike, N1JEZ
AMSAT #29649
Local Area Coordinator
"A closed mouth gathers no feet."
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