Bob,
?
according to this table
?
70 mm2 is AWG 2/0
?
I run 2 conductors from the alternator to the
batteries /amplifiers in the trunk.
The cable is neoprene insulated welding cable, size
garden hose. Lugs are also from the welding shop. With my "old" setup the B+
voltage measured inside the Henry SS750 on the push pull amplifier board sagged
to 11.0 VDC. Mind you the voltage drop over the INTERNAL cabling including the
little 50 amp rated feedtru was?a massive 1000 millivolts.
?
After measurements the teenie weenie lug on the B+
cable and the little screws on the feedtru proved to be the culprit so PE1LRF
machined 2 massive feedtru insulators for me and I fitted both the B+ and mass
cables with 8 mm lugs and 8 mm bolts.
Also I redid the B+ distribution rail inside both
the SS750 amplifiers.
With one amp I can now keep the voltage at 12 V DC
loaded with a carrier. In SSB this will be a bit better due to the lower
average?current draw.?
?
Cheers, Dick
?
?
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----- Original Message -----
Sent: Monday, January 08, 2007 7:01
PM
Subject: RE: Re: [ham_amplifiers] Re: The
real benefits of running qro.
Dick that sounds good.?
You¡¯ve spent some time on the project.
Here¡¯s my thoughts on the DC
buss¡? Lead Acid Batteries don¡¯t supply much power.? They are native
12.8 VOLTS.? ?The Alternator supplies all your voltage up to 14
Volts.? When you load down the circuit past what the alternator can
provide you start drawing from the batteries.? Like at a stop
sign.
If you look at wattmeters between
cruising and idling you¡¯ll see what I mean.
The car stereo guys have really
made ham radio mobile better¡
BUY the 1/0 or 2/0 silicon stereo
wire and run a positive AND A NEGATIVE back to your amplifier location.?
I don¡¯t know how that compares to your 70mm2 wire?? Also ground to the
chassis at the amplifier.? I was informed by the BIG mega watt stereo
guys that vehicle grounds are not good enough for serious current.? I¡¯ve
noticed a difference.
I do tie in right at the batteries
under the hood myself.
Go to as large an alternator as
you can get and charge your batteries under the hood.? The 2/0 wire will
have very little voltage drop.? The best things for back at the
amplifiers are the new 5 FARAD capacitors.? They need to be charged up
very carefully.? These things are dangerous.? They look just like a
battery and have terminals for the big wire right on the sides of them¡?
They will charge UP TO your maximum voltage 14V and not surface charge like a
battery will¡ They provide 22AMP HOURS at full voltage!? Where a battery
sags down to 12.8 as soon as the alternator loads the big caps slowly
discharge from full voltage.
YES these are all tricks I¡¯ve
learned from these crazy stereo guys.? They¡¯ve got shoot out trophies
from the big national audio shootouts.? Things like 163 DB loud stereos
in a car stuff.? They are drawing like 500 amps or more in a mobile
unit.
I also run the radio separate on
another 4 gauge run from under the hood.? I use all the fancy stereo
fuses and distribution blocks.
I ALSO use all these things in my
shack to distribute power around my operating desk from a pair of ASTRON
RM-70¡¯s.? These stereo guys are great, except when they drive down my
street at midnight.
BOB DD
From:
ham_amplifiers@yahoogroups.com
[mailto:ham_amplifiers@yahoogroups.com] On Behalf Of PA3DUV
Sent: Monday, January 08, 2007 6:21
AM
To:
ham_amplifiers@yahoogroups.com
Subject: [Norton AntiSpam] Re:
[ham_amplifiers] Re: The real benefits of running
qro.
Thanks for the info. Nice to know
that others are working in similar projects.
Please find some pictures in the
photo-section showing my 2 kW mobile setup.
I use two Henry SS750 amps, into a
4 kW combiner.
The antenna is a HiQ 5-80 HP
version. To remote control the amps I build a break-out box, so I can use one
remote control?on 2 amplifiers. Two 70 mm2 neoprene welding
cables??are used to supply the DC to the
amplifiers.
The power supply needs to be
beefed up. I will install two 230 Ah 70 kg AGM batteries in the trunk. The
current two 60 Ah are barely enough to power one SS750, together with the
alternator.
A single ?SS750 delivers 1100
watt output on 40-160 meters when connected to a stiff DC
rail.
----- Original Message -----
Sent: Monday,
January 08, 2007 12:38 PM
Subject: RE:
[ham_amplifiers] Re: The real benefits of running
qro.
I HAD
TWO SGC POWER CUBES, over.. Work good but will trip out for
anything
fast, always resetting them. The remote control heads are the
only way.
Have new larger amp plan going together soon for the "new"
pickup. Recently
sold the remote head 706 and going to mount a 756PRO II.
Between a couple
of my friends, we're having a mobile war. Total keep up
with the Joneses.
One upped the anti when he bought one of those
Chinese 4KW generators to
mount on the rear of his SUV on a hitch mount.
I have a 5KW Makita I'm
considering mounting in the pickup bed next to
the auxiliary fuel tank. :-)
Its sort of a pain when sitting in an RV
park at 10PM idling the truck or
running a generator to keep power to the
amp. Would be better if could just
jumper over to park power easily / amp
runs full power on 120/240.
My buddies and I have all gone from Texas
Bug Catchers to the big Predators.
My bug arced and caught on fire
driving in the rain. Burning plastic parts
were hitting the windshield
and it was too hard to change bands while
driving. Could never get my
wife to change the taps while moving. It's a
real pain carrying a ladder
in the box all the time.
I have a custom front mount on my crew
dually to bolt on the PRED. (I pull
a fifth wheel or car trailer out the
back depending on what I'm doing.) Its
really easy to tune now, just look
through the coil cover and see how much
coil is exposed, with a little
experience I can get within a couple clicks
every time.
My
reasonable goal is consistent-reliable 1500 watts out mobile. The next
problem to overcome is amplifier heating. I don't want blowers running
in
my ears.
BOB DD
-----Original Message-----
From: ham_amplifiers@yahoogroups.com
[mailto:ham_amplifiers@yahoogroups.com]
On
Behalf Of pentalab
Sent: Monday, January 08, 2007 3:32 AM
To: ham_amplifiers@yahoogroups.com
Subject:
[ham_amplifiers] Re: The real benefits of running qro.
--- In ham_amplifiers@yahoogroups.com,
"bendeguz007" >
wrote:
>
>>
> SO WHAT, now you have EXTREAME QRO amp, they hear you: 200 dB over
S-
9
>
> BUT you have NO antenna to HEAR them!
> I'd
rather hear them, then talk to them with my 100W mobile with a
Hi- Q-HF
antenna.
>
> Charlie, VA7HIQ/W6
### HI-Q traps are
precisely why traps in tapped tri band yagi's
usually melt ! My buddy's
TA-33 jr... with just a sb-220....
looked like u hit it with a propane
torch... and all the fiberglass
coil forms were all melted. The new
mosely pro- series
tribander's.. allthough rated at "5 kw" will
handle 600 W ccs max..
then they are toast too. The circulating current
is so high.. the AL
wire used gets too hot.. and
melts the forms.
### If u want real hi power mobile... 1/2 the
problem is just
generating it. Of course Dahl makes a special 3 phase
plate xfmr...
for the 11m mobile ops!
### The bare min u require
for semi reliable 80-40m operation is 500
w. Going from 100w to 500w is
7 db.. a huge amount. On ssb
that's easy... since the average current is
so low.
### Like Doc Bob sez.... then u gotta debug for RFI etc. I
knew one
guy who had his big tube amp fired up in his mobile.... and
going down
the highway... killed the ignition dead in a van that was in
the next
lane over. He did it again to a few more vehicles[including one
cop]
while stopped at red lights !.. a real hoot.
### There are
loads of those IM Italy class C distortion box's out
there... mobile.
The SGC 500w unit does an easy 800 w.
later... Jim VE7RF
>
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