I responded off list to Steve previously, but I'll reiterate for the list.
My vehicle is a Honda CR-V. I run 10 bands - 50W on 6, 150+ on 2, 100 on 222
and 432, and various amps on the uwaves. I run everything off the car 12V bus
and keep the car running when I am stopped and operating. No discernible
ignition noise at idle. I don't operate while driving. Operating position and
all gear is in the back seat.
Since very few laptops will work directly on 12V, I run an aftermarket DC-DC
converter from Mobility Products to power my 10 year old Toshiba. There is no
noise from the supply, but the laptop is pretty noisy itself.
Knowing that 120V AC inverters generate hash, to avoid conducted EMI, I use a
deep cycle AGP UPS battery to power the Black & Decker 750W inverter (Wal-Mart,
<$70). Both sit on the floor in the back of the car, behind the rear seat,
with no shielding. The rotator is a HamIV. To conserve the battery, I have
disconnected the inverter when I am driving to the next stop.
Since up here in the wilds of Maine, almost everyone is to the west and south
of me, so I try to park so I don't have to move the antennas much. At first,
when peaking antennas, I would turn on the inverter to use the rotator. I
subsequently discovered that the inverter generates a miniscule amount of hash
on 6m, but doesn't seem to affect the other bands at all. Accordingly, I got
lazy and just leave it on all the time. After a weekend of roving, the battery
voltage reads almost the same as when I started.
Does leaving the car or inverter running raise the noise floor? It would seem
likely that it would, but in attempting to hear a very weak signal, I have shut
both off and noticed no difference.
Biggest noise source - laptop. Liberal use of ferrites might help. Best
solution - paper logging.
2nd biggest noise source - Garmin GPS. Solution - turn it off. I don't need
it except when I'm driving.
So - it works for me. YMMV.
73,
Bruce WW1M
>
>Why not run the Laptop off 12V and just use the inverter to power the
>rotor when needed (turn it off when not turning the antennas). The
>hash would off most of the time. Another way is use a 12V Rotor
>(like the Alpha Spid).
>
>VRY 73
>Bob Cumming
>W2BZY
>QRV 160M - 9CM + 3CM (5760 next)
>from EL98hr
>
>At 02:21 PM 4/14/2008, k4gun@comcast.net wrote:
>>Well, that is something to consider, but I'm not sure it really is needed.
>>
>>Allow me to describe my power needs and the physical locations of
>>everything. I'm running one IC7000. Only 6 meters will be done
>>with full power out at the radio. I have amps for 2 meters and 432
>>(200 and 100 watts respectively) and have ordered the 60 watt output
>>transverter for 222 from Demi. All electronics will be run off the
>>auxiliary battery which is mounted in the tool box in the bed of my truck.
>>
>>The tool box itself is steel. Its not one of those aluminum
>>models. Its big and very heavy and has only two access holes in the
>>side. I have a 5' tower section that will be bolted to the side of
>>the tool box in the bed of the truck. The third leg of the tower
>>will be bolted to a steel cargo divider in the bed. I have an HD-73
>>rotor that is mounted on a steel plate at the base of the tower and
>>an 8' mast sticking out the top. Antennas are the Directive systems
>>Rover Specials for 144, 222 and 432 and a Parr Stressed Moxon for 50 MHz.
>>
>>The inverter will be mounted within a couple of inches from the
>>battery inside the metal box. There will be large ferrite beads
>>clipped on to the lines at the exit point from the box. The metal
>>box is directly underneath the antenna array.
>>
>>I don't see any reason why I would be rotating the antenna while
>>listening, but I guess that's possible. I will be running the
>>laptop at all times though.
>>
>>Under these conditions, do I really need the pure sine wave and if
>>so, how powerful do I need?
>>
>>Steve
>>
>>-------------- Original message --------------
>>From: "dbubke@juno.com" <dbubke@juno.com>
>>
>> > Steve,
>> >
>> > I am transitioning my modest rover setup, just like you, from
>> loops to yagis.
>> > When I looked at the cost of upgrading my 14V power wiring to
>> supply 25-35 amps
>> > (AWG 2 or larger)at 14 volts with minimal loss (0.2volt) and
>> adding an inverter
>> > for a rotor, I decided it was time to take a generator and power
>> supply along
>> > instead. This is untried in the field as yet.
>> >
>> > I ran some tests on RF output of my rigs, at voltages varying
>> from 11.15 - 14.2
>> > volts, and was surprised at the 25% reduction in RF power output
>> at 13.8 volts
>> > and 50% reduction at 12.6 volts.
>> >
>> > Also tried a well known dc-dc booster to maintain 14 volts. It
>> worked okay at
>> > loads of 15 amps or less. Not what I need.
>> >
>> > Just my 2 cents.
>> >
>> > Dan K6NKC
>> >
>> > -- k4gun@comcast.net wrote:
>> > OK... who has a "hash free inverter"?
>> >
>> > Steve
>> >
>> > -------------- Original message --------------
>> > From: frank bechdoldt
>> >
>> > >
>> > > Most inverers will create RF hash along with most ac/dc converters for
>> > laptops.
>> > > You would need to ask wo has a hash free inverter on the market.
>> > > _________________________________________________________________
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>>
>> > > intouch_042008
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