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General Notes, a Work in
Progress with Ongoing Additions
6/20/2000
I know from experience that HF and VHF operation does not affect the
two computers in VW Vanagons 1989 - 1991. The 1989 model has some
electrical noise from the electric fuel pump but it is tolerable. I
worked the Russian island, Sak-Halin, just north of Japan twice while
mobile.
Make sure your car is in
very good repair, check the fan belts and general condition of the
engine wiring. It costs $80 to replace the VW alternator bearings at
an auto-electric shop while a new unit from VW Parts is over $250 and
difficult to find. The bearings went out at 70,000 miles.
Replace or clean the
battery terminals.
The exhaust pipe is a
great antenna transmitting noise into your HF radio. While you have
your hands dirty, ground the tip of the exhaust pipe to the frame but
first clean the connecting points down to raw metal then after making
the ground, protect these points with good weather proofing. Most new
cars have ground straps in the corner of the engine hood. Remove the
straps to inspect the ground points, clean and then replace.
Your 100 watt output SSB
rig needs over 20 amps of current at peak output. After a few hours
of transmitting you'll like to start up for the trip home so do
yourself a favor, install a new car battery or add a secondary
battery. You want to be mobile on the highway, not waiting for a tow
truck.
Turning up the
Alternator Charge
I'm writing this to
myself as a reminder and for those who are fearless. VW, unlike their
German brothers, keep the charge rate under 12.5 volts. Other VW
folks told me to put a 100 amp silicon diode in series with the
alternator rotor field to boost the alternator output an equivelant
amount up to 14.5 volts maximum. Sounds like an easy way to raise DC
voltage as long as the battery is not overcharged. I've measured
other cars and find most to be as high as 14.5 volts at high engine
idle and all lights turned on. The VW measures about 12.5 VDC with a
new battery and like new connections.
Engine Noise
Corrections 3/12/2001
Richard Ulrich K2KOQ has
this recommendation for ignition wires but the web site if off the air.
"...source for noise
suppression wires that REALLY work. I used them on a Ford Crown Vic...
worked great. Had a friend with a GMC that was so bad 2M FM didn't
work! ...set of these wires fix it 100%. You need to get the "CN"
series wires."
richard@ulrich.com
http://www.richard.ulrich.com
Thanks for the excellent
information Richard. 73 ... Bill
My experience follows:
Engine noise is something most of us have to deal with so locate some
braided cable for grounding strap. This is similar to coax shield and
is available in war surplus and very large electrical supply stores.
Mine is double woven and 1" across so it should last for a while and
Radio Shack or marine (boat) supply houses have the terminal ends.
Check out marine supply stores first as they have some very serious
hardware.
For starters, ground the
tail pipe then each corner of the engine hood at the hinge location.
You might check under the hood of a new European car because most of
them have this item. Bypassing the electric fuel pump with .05
capacitors could be more difficult so you should consult your mechanic
or other authorities. All long conductors are great antennas so
bypassing at each end might be helpful.
I've heard that silicon
promotes corrosion from the gases it emits while curing so use
something else to protect connections from corrosion.
Engine computers are out
of my area. You are on your own but there are occasional articles in
QST mentioning individual cars that experience problems. Oh yes, RFI
is not limited to your neighbor's TV set, my 440 FM sigs get into the
XYLs Mercedes up to two blocks away. Well, at least I'll get the
last word in and from a safe distance too .... yea !
Future Topics:
Battery Wires, size
and routing
Cell mount and H.F. mount, the toughest part.
Tuner location and wire to antenna base.
Tuner lock-tune control box. Needed to lock the tuner from changing.
Battery charge indicator. Some add-on 12 volt analog meters draw 2
amps! Radio Shack makes a very small DVM for $14 and runs forever
on it's internal battery. Permanently mounting this flat read out
on the dash or radio is possible because of it's small size.
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