[aprssig] Considering buying a D7 - Some Basic Questions

Stephen H. Smith wa8lmf2 at aol.com
Fri Mar 28 12:03:04 EDT 2008

Steve Noskowicz wrote:
>   It'll be nice to have the portable APRS as well as the Sky Command 
> capabilities.  Neither the latest QST article on the (G), nor the original
> article gave info about what is included with the radio (except the GPS cable).
>  Specific questions:
> Does it have an in-radio charger?

The radio's DC input can accept 12 VDC directly.  With 12 VDC in, the TX 
power increases over that from the 9.6 VDC battery alone.

> If so, is it a wall transformer / power supply with that really small inverted
> (female) power plug?

Yes, it is a 12 VDC "wall wart" with the submini coax power plug on it's 

> Can the radio transmit on the above charger?

No.  The charger can't supply the full TX current drain. It falls out of 
regulation and puts AC hum on the TX signal.

> Is the supplied GPS cable &  2.5mm connector similar to the D700 one? (very
> thin, soft and fairly long)

It's the same cable with the same pinout.

> What is the PC connector?

Another 2.5mm stereo mini-jack. 

> I'm pretty sure the interface is TTL and that there are level converter designs
> on the web.  (I've designed and built my own level converters for the 706 and
> TH-F6A)

You don't need any level converters.   The serial I/O works directly 
with standard RS232 serial ports.  It's NOT like earlier serial I/Os on 
Kenwood's earlier HF rigs that required optional external adapter boxes 
or level shifters to work with normal serial ports.

> Comments welcome on:
>     I believe I've heard that the battery life is a bit short.  The ARRL
> articles say 90ma drain Rx.  That's fairly high.  The one they are selling is a
> 9.6v. 600mah battery. instead of the 6v. 650 mah.  which amounts to 6-2/3 hours
> Rx.

Actually the run time would be less for that mA-h battery capacity since 
you wouldn't want to TOTALLY run down the battery before recharging.


Stephen H. Smith    wa8lmf (at) aol.com
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