Richard -

Here are the FAQ from the SGC web site:
http://www.sgcworld.com/products/239/239faq.html#1

Note: this question is in reference to the SG-239 SuperTuner

#1 If I do not switch on the 12 VDC power to the tuner is the tuner always
in the bypass position so the RF goes right through it and nothing is tuned?

At any time12 v is not applied to the tuner, you will have total
inductance 16 mH (microhenry), in series with your antenna.
To bypass the tuner you must:


A) Have 12v applied. Note: If you have 12v applied then coupler would
be on - If no TXMT occurred, it would be in bypass mode.

B) Reset the tuner by tuning 12v DC off then on or with reset or
Smartlock.


SGC SG-230 SuperTuner
http://www.sgcworld.com/products/230/sg230.html

http://www.sgcworld.com/products/Couplers/index.htm

SGC, Inc.
1-800-259-7331
13737 SE 26th St., Bellevue, WA 98005 USA
Tel: 425-746-6310 | Fax: 425-746-6384
E-mail:

Greg
w9gb

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"Richard C. Ferryman" wrote in message
...
Can someone tell me what the SG-230 ATU does when powered off? Is the
antenna left connected / grounded or what.
I want to use one on maritime mobile and will be calling on certain
frequencies for mail transfer but in between will be scanning and
downloading FAX, RTTY and NAVTEX on frequencies from 490 kHz upward.
Transmitting on ham bands 80 through 15 M only. I'm wondering what
sort of signal will be passed through the ATU when not in use on the
ham bands and not tuned (receive only) and when powered off.
Richard