Bil wrote:
After checking my zinc anode, I'm fairly certain I'm getting
accelerated erosion of my shaft zinc anode when transmitting Sailmail
e-mail via my HF radio and PacTOR modem.

Sailmail and the PacTOR modem drive the HF radio (an ICOM IC-M710)
fairly hard.

Does everyone transmitting with a PacTOR modem suffer accelerated
erosion of their zinc anodes? Or is this something specific to my
installation (and can be corrected)? If the latter, what should I look
for and correct?

Cheers

Bil

Look at

http://www.sailmail.com/grounds.htm

Probably the best article on grounding available
Gordon

Agreed that is probably the best description of a good grounding system. I
have followed it including the isolation caps between the RF ground and
engine/keel and a DIY DC block on the VHF coax but I still have one path for
RF to get to the DC ground. The power line to the SSB. With the coax from
the SSB to the tuner disconnected the DMM shows infinite resistance. With
the SSB connected (but not on) I get 8 ohms. I think I need to add a DC
block on that coax too.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Gordon" wrote in message
...
Bil wrote:
After checking my zinc anode, I'm fairly certain I'm getting
accelerated erosion of my shaft zinc anode when transmitting Sailmail
e-mail via my HF radio and PacTOR modem.

Sailmail and the PacTOR modem drive the HF radio (an ICOM IC-M710)
fairly hard.

Does everyone transmitting with a PacTOR modem suffer accelerated
erosion of their zinc anodes? Or is this something specific to my
installation (and can be corrected)? If the latter, what should I look
for and correct?

Cheers

Bil

Look at

http://www.sailmail.com/grounds.htm

Probably the best article on grounding available
Gordon

Glenn Ashmore wrote:
Agreed that is probably the best description of a good grounding system. I
have followed it including the isolation caps between the RF ground and
engine/keel and a DIY DC block on the VHF coax but I still have one path for
RF to get to the DC ground. The power line to the SSB. With the coax from
the SSB to the tuner disconnected the DMM shows infinite resistance. With
the SSB connected (but not on) I get 8 ohms. I think I need to add a DC
block on that coax too.


To me, that means the ssb DC ground must read 8 ohms to the shield
of the rf out cable of the ssb. I suspect you're reading thru some
components that probably, effectively, goes away when the unit is
operating. Does the reading change when you reverse polarity?
G

Thanks to Gordon, Manlio and others for their helful suggestions and
reports.

I've determined that my HF ground does NOT connect to the engine or
other underwater fittings, only to the chainplates etc.

And that one sistership also reports accelerated erosion of her prop
anode when making passage, but not when in dock. And that sistership
has a capacitor-bridged break in the radio counterpoise, as per the
Stan Honey recommendation in the article noted by Gordon. The
sistership also uses her HF Pactor modem extensively and does not
spend much time connected to shore power (far less than I do).

I've purchased a silver/silver chloride half cell and aim to spend a
few hours following the Nigel Calder test suite detailed in his
article at http://www.proboat-digital.com/proboat/200604/.

Any other tips?

Cheers

Bil

Bil wrote in news:63daeb65-8bc1-48cd-bd13-454bfb6a8c79
@b2g2000hsg.googlegroups.com:

http://www.proboat-digital.com/proboat/200604/

God, what a SPAMMER that site is!