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Re: hi power mobile
Robert B. Bonner
There is very little tissue heating at HF.
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As you start passing through Vhf to UHF you have severe issues. Some very serious tissue effects can happen at 432. My 432 amp can generate 2KW out. With big antennas at those frequencies ERP's in the mega watt range are possible at ham power levels. The original microwave ovens ran around 900MHz well there's another ham band too. You have more problems stopping pacemakers at HF. I wonder if there could be any liability at a stop sign if the person in the car next to you keeled over because you were trying to work the 7Alpha on 20 meters from the car? At the old WB0DRL VHF/UHF contest station they tuned the amps with microwave leakage detectors, you know the tool for testing ovens. All the stations had them. The shack was RF tight, however when the door was opened the detectors would all start banging off the pegs to the CW. Everybody would scream "Shut that door" I declare Ham Radio is completely safe. What? (Battle Cry heard from the LT as you charge the enemy with only a knife in your teeth) YOU WANT TO LIVE FOREVER? BOB DD -----Original Message-----
From: ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of badgerscreek Sent: Wednesday, January 10, 2007 5:34 AM To: ham_amplifiers@... Subject: [ham_amplifiers] Re:hi power mobile I think those Yellow Top Batteries are called Optima Batteries? I dont know why nobody is concerned about having their brains so close to the antenna? I mean sitting in the near field of the antenna running 1 or more kilowatts at the higher frequencies would have me worried. Maybe the adrenalin rush is more potent than worrying about your health, or maybe theres no danger? Greg --- In ham_amplifiers@..., "craxd" <craxd@...> wrote:
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Re: hi power mobile
PA3DUV
¿ªÔÆÌåÓýWill,
?
Thanks for the input.
After reading all the post on this subject I will
finish the power supply as follows:
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8 x 2 volt 230 Ah cells feeding the amplifier
stack
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16 volt 3 stage charger, input voltage 230 V
AC
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12 VDC => 230 VAC sine wave inverter to supply a
limited 230 AC?for the charger ?while driving
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an external 230 VAC connector on my trailer hitch
so I can charge the batteries when the car is on the driveway
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A better alternative would be to install a second
16 volt DC alternator, but there is simply no space for a second
alternator.
?
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Cheers, Dick
PA3DUV
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Re: Tom's Tubes - Tom Hix, W4TH, SK
Joe Subich, W4TV
Per information posted to the South East DX Club reflector
yesterday, Jim, K4JRS (k4jrs@...) is liquidating the inventory of Tom's Tubes. Information from another source says that Tom's home has already been cleared and Jim is simply disposing of the remaining inventory for the family. 73, ... Joe, W4TV --- In ham_amplifiers@..., Tony King - W4ZT <w4zt-060920@...> wrote: management.
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Re: hi power mobile
On Jan 10, 2007, at 3:33 AM, badgerscreek wrote:
I think those Yellow Top Batteries are called Optima Batteries?** In the early 1960s I used to work at Raytheon, Point Mugu. Bill Hunter, W6YK, worked in the engineering division. On cold mornings, he would warm his hands on the 300w X-band doppler radar. Bill did not die young. ...R. L. Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org |
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Re: hi power mobile
craxd
--- In ham_amplifiers@..., "pentalab" <jim.thomson@...>
wrote: amplifiers andyouvoltage requirements.##### I have zero experience with it. I was just waiting for to come out of the wood work.... since I knew you guys had thisdown pat... and was all old news. The deep cycle communications Right now, they're running those yellow top batteries with the spiral cells. They claim these to be the best. Also, there's really no limit to the batteries that you parallel together to get the power required you need. The more batteries, the longer you can run. I've seen the big 24V batteries used in diesel rigs too ran in these set ups. The ones you want have the largest amp-hour ratings. and runOneparallel / series combos of standard car batteries (or standardand deepcycle, if they are smart) to have a 24 volt electric system. alternator, and a pair of batteries will power quite a largesystem, as They'll use like 6 of the Leece Neville alternators under the hood to power the big solid state amps. Some have used generators that can provide 115/230 Vac too ran off the belt.
Right, not a lot has been published on this as it was all done sort of under the table away from the FCC.
Best, Will |
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Re: hi power mobile
craxd
--- In ham_amplifiers@..., PA3DUV <pa3duv@...> wrote:
The largest one I made and sold was a 200 amp. I designed a 300 and 400 amp but never built one as I never had an order for one over 200 amps. Anyhow, the ones I built used 10 pass transistors connected in parallel (I forget the part number but they had a TO-3 case), which had a maximum dissapation rating of 300 watts each, and a 30 amp current rating running in the safe area at the specified voltage. These were driven from a variable regulator circuit. They were mounted on a large heatsink I had made from sheet aluminum bent into C channels where one was slightly narrower than the other so they stacked together making the fins. They were stacked up to make a base about 3/8" thick. I'd have to look at the prints for the other dmensions like width and length sense it's been a while building one. Your correct, there's heat generated by the pass transistors as it works the same as any series pass power supply. As was mentioned by another, FET's can be used here also. The pass elements I used were NPN transistors. Each had a 0.1 ohm balancing resistor in series with each emitter lead. The charging circuit was switched by using starter solenoids rated at 400 amps each. The RF keyer turned the regulator on then keyed the amp afterwards so the amp would have power before the RF got to it. This was done by a simple relay timing. For a ham rig, you can do this without a RF keyer of course using the keying from the rig like on running an external amp. The problem of the switching here though creates a slight delay after the mic is keyed before you can broadcast of about 1/2 to 1 second due to the speed of the starter solenoids and relays. The regulator has to come on and supply the amps source voltage before the amps RF relay closes. So the regulator keys the amps RF relay. The regulator box and batteries were mounted in the trunk or in the back of a Bronco, Suburban, or van. The remote that mounted under the dash had an on/off switch, volt meter, and voltage adjustment pot on it. Best, Will |
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Re: hi power mobile
pentalab
--- In ham_amplifiers@..., 1800 Toll Free
<TollFree1800@...> wrote: and voltage requirements.##### I have zero experience with it. I was just waiting for you to come out of the wood work.... since I knew you guys had this down pat... and was all old news. The deep cycle communications batteries work pretty good. ### I also read in an old QST... where they would use 2 x batteries in series.... like those used in golf carts..... but one was 6 V... and the other was 8 V. [didn't even know u could get deep cycle batteries... big ones... in 6 + 8 V ] Then ur car regulator would charge em to 14 .3 V..... then with engine OFF.... ur small 706-mk-2-G would last way longer. That setup was also used in some Field day event's. They use a charging system consisting of a 24 volt alternator, andrun parallel / series combos of standard car batteries (or standardand deep cycle, if they are smart) to have a 24 volt electric system. Onesystem, as ### Don't some of em use train alternator's ??? Think they were split stator, dual rotor.... or split rotor, dual stator... made by Neville Leece.... at 1000 A per stator ?? Or was this for the tube setups ?? ### I still haven't seen any detailed website on this hi power mobile stuff. Trying to generate the power is a huge project in itself. RFI, etc... Rf decks... is another issue. You are right... hams are just trying to reinvent the wheel. Later... Jim VE7RF --Toll_Free |
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Re: The real benefits of running mobile qro.
PA3DUV
¿ªÔÆÌåÓýPhil,
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On next occasion I will open the SS750 amp and take
some pictures.
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What I did to reduce the voltage drop is the
following:
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1. replaced the feedthru with a larger one, and use
a M8 brass bolt with siver sodered brass nut + washers to get the B+ into the
chassis.
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2. replaced the tiny 5 mm lug on the B+ wire with a
large 8 mm lug
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3. beefed up the B+ wire to the breaker and from
the breaker to the relay
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4. the B+ wires to the 4 PA modules are connected
to a brass strip on the relay.
In one of the amps these wires were clamped into
the brass strip with a small steel set screw. I have removed the set screws and
crimped/soldered lugs to the 4 B+ wires and have clamped them top/bottom on the
brass strip. This has increase the contact surface considerably.
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5. The aluminum angle strip (backpanel inside)
?where the ground wires terminate is now connected to the backpanel with a
larger M8 bolt, this bolt is also used to connect the - cable on the outside of
the backpanel.
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Cheers, Dick
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Re: hi power mobile
PA3DUV
¿ªÔÆÌåÓýWill,
?
How does a series regulator for 300 amps look
like?
The efficiency from such a regulator seems to
questionable, the voltage difference x current is obviously dissipated and
turned into heat. ([22 loaded?- 16] x 300 =
1800 watt)
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Re: hi power mobile
It's kind of funny watching the thread about the mobile amplifiers and voltage requirements.
Here, we learned long ago (on 11 meters) how to fix this problem. The 11 meter crowd calls it a "dead motor maul", and it's nothing more than a bank of pass transistors (or mosfets, if the builder knows what he's doing) that act as a regulator. They use a charging system consisting of a 24 volt alternator, and run parallel / series combos of standard car batteries (or standard and deep cycle, if they are smart) to have a 24 volt electric system. One alternator, and a pair of batteries will power quite a large system, as long as the number of active devices in the regulator is up to the job. This allows you to do a number of things, but vary the collector voltage from < 11 volts to > 20 volts is possible. Run a regulator to the bias section of the amp to keep bias in check and runaway in check, and you can run 16 volts on the collectors easily. I have a 12 volt 16X2SC2879 amplifier that produces > 2400 watts PEP at 15 volts. This is a bootleg cb amplifier produced by Messenger years ago. It has a simple 10 meter filter on the output, which I can't measure the effectiveness of due to lack of equipment. Stock, it ran > 1 volt of bias on the base of the transistors, and would toast them at > 14 volts (like, a stiff charging system, with long periods of keydown, here's another 300 dollars in transistors). I redid the bias circuit with different diodes (a diode feeding / clamping each pair of transistors) and a 12 volt regulator with a pair of pass transistors feeding the bias regulator. This keeps things a lot better running higher Vcoll than afforded with the stock "regulated" system of nearly any amplifier. --Toll_Free |
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Re: hi power mobile
craxd
--- In ham_amplifiers@..., "pentalab" <jim.thomson@...>
wrote: system.. instead of 12 v ?a 28 V... 3 phase alternator. We made some tube mobiles this way back in the late 70's to early 80's. You took the 14V 3 phase AC and powered a HV transformer with it. The large tube amps they use on those 11 meter shoot outs are set up this way. Galaxy Transformer up in New Jersey makes the transformers for several amp builders. You could still run the vehicle on theone battery... and the other half of the vehicle's 12 v stuff.... onthe other battery. Yup, and you have way less current draw meaning you don't have to handle all that large battery cable to hook a 12 volt amp up. I also made what was called a motor maul which is really a voltage regulator that ties to 2 banks of 12 V batteries in series. It works from RF keying. During Idle, the batteries are in parallel and are being charged by the alternator. When it's keyed by the RF sensing circuit, it places the batteries in series making 24 V then runs that through a variable series regulator. When using 2SC2879 transistors, you can run them at around 18-19 Vdc and get Mo-Power from them and they run just fine. At 12 Vdc, it cuts the power by about 1/4. Heavier heatsink is recommended though when running one class AB at 18 Vdc.
Best, Will |
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Re: hi power mobile
Peter Voelpel
I do the latter with my IC-2KL, 4 batteries are switched in series on
transmit and parallel on receive 73 Peter ________________________________ From: ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of pentalab You could use something like 2 x cat batteries in series.... with a 28 V... 3 phase alternator. You could still run the vehicle on the 12v from one battery. .... or run half the car's 12 v stuff on one battery... and the other half of the vehicle's 12 v stuff.... on the other battery. Even a 50 v system.. with 4 x batteries in series would work. |
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Re: hi power mobile
On Jan 8, 2007, at 5:07 PM, pentalab wrote:
One would think the logical way to go, would be a 24-26 v system..** In Europe, Diesel vehicles are already using 42v electrics to make for easier starting in cold weather. At the current price of copper, the savings per automobile are considerable. R. L. Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org |
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hi power mobile
pentalab
One would think the logical way to go, would be a 24-26 v system..
instead of 12 v ? You could use something like 2 x cat batteries in series.... with a 28 V... 3 phase alternator. You could still run the vehicle on the 12v from one battery. .... or run half the car's 12 v stuff on one battery... and the other half of the vehicle's 12 v stuff.... on the other battery. Even a 50 v system.. with 4 x batteries in series would work. Later... Jim VE7RF |
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Re: The real benefits of running qro.
Phil Clements
After measurements the teenie weenie lug on the B+ cable and thelittle 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 SS750amplifiers. With one amp I can now keep the voltage at 12 V DC loaded with acarrier. In SSB this will be a bit better due to the lower average current draw. Dick, Please expand on all the mods you did to your SS-750. I would like to fix mine also. Any pix, diagrams, etc. appreciated. I did the feed-thru mod already...waiting to see what you did on the interior of the amp. (((73))) Phil Clements, K5PC |
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Re: The real benefits of running qro.
FRANCIS CARCIA
or hello power bill
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Bill Turner wrote:
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Re: loading coils.. + corona effects ?
pentalab
--- In ham_amplifiers@..., "Peter Voelpel" <df3kv@...>
wrote: with reasonable wire size ### Point well taken. I thought of that this am, while driving to work. Parallel resonant traps are a whole new ball game. I also noticed on some of these 80m yagis.. that use loading coils... that the aluminium coils are actually heliarc welded at each end... to reduce joint resistance to nil. ### I don't have any experience with corona balls at all. Telrex used to use corona balls on the tips of the de on the 10m models. The anti- vibration loops on some telrex yagi's would serve the same purpose. ## The 11m boys tell me on their 11m yagi's... they will either use corona balls... or use soft solid aluminium inserts on the ends of the de... with the inserts ground down to look like u know what ! ## I think the 2m moon bounce guys will grind the sharp edges off all their solid al els. ## anybody know how much power is required to produce corona on the tips of ur typ 20/15/10 m mono band yagi? What about loaded 40m yagi's ? And what about typ 160/80m GP ? And what about stuff like a shunt fed tower. ### aside from glowing blue at night... what other ill effects happens ? Do the tips of the els burn off? Now I know what Dr Bob is gonna say... just use a pair of theose 60's style copper toilet tank float balls !! Don't laugh... that's exactly what radio HCJB did on their yagi's... and severely detuned em in the process.... hence their quad inovation. Story is... HCJB was running 10 kw AM [50 kw pep] output when this all occured. ### telrex's old anti vibration tips looked like one 1/2 of a 60's kitchen eggbeater. Whatever get's used... u don't want to restrict water egress from the tips of an el... leave it open to breathe. ## who's got experience with this issue.. I don't. Later... Jim VE7RF [mailto:ham_amplifiers@...] On Behalf Of Dickqro. 80 centerloaded vertical on my car. |
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Re: The real benefits of running qro.
Robert B. Bonner
¿ªÔÆÌåÓýOK rog¡? this stuff is beyond 2/0 its 750MCM two steps up¡ ? Yeah funny how the manufacture (Henry) even lets you down¡? 1V drop inside their amp chassis.? They were never the brightest bunch over there.? Good job on the feedthru! ? But see that¡¯s what I am saying about using batteries, you¡¯ll add them and still have the same voltage at the board.? You might pick up 0.8 volt.? That in my mind isn¡¯t worth the 350 pounds of battery and box against the fuel economy. ? Lead acid batteries are 12.8 V.? They charge at 13.6V.? Car electrical systems run at 13.6-14V as the alternator must provide all the juice for the vehicle operation. ? Now imagine what you could do with the full 14V at the boards¡? That¡¯s our goal.? J ? From:
ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of PA3DUV ? 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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Re: The real benefits of running mobile qro.
Robert B. Bonner
¿ªÔÆÌåÓýDick I feel your pain¡? WOW those are serious batteries.? Only 155# each plus the battery box you¡¯ll need to hold them.? That¡¯s serious weight to haul around. ? If you remember what I was saying earlier that voltage is the important thing for the amps to crank. ? For instance the SGC power cube was rated 10-18 volts.? I was talking to a guy on 20 meters one day while I was driving somewhere and he said, OH yeah hey how many volts do you have on your cube? ? Well car voltage 13.8V under load¡? Well¡? He says I have a homebrew power supply here and use the power cube at home, the supply is set to run 18V right at the cubes max voltage.? It puts out 1000Watts and runs cooler than if I run the voltage lower and put out 700. ? I found that rather interesting.? I also wondered about running cooler?? Didn¡¯t seem logical to me but I¡¯m open minded.? Well I drag one of my units into the house and crank up my Astron 70 PS as far as it will go¡? 15 volts.? Yes the amp cranked up another 150 watts out.? Whether it ran cooler or not I just don¡¯t know but I sure liked the extra power out. ? This to me said a couple things.? Higher voltage is good, higher current is bad and that my mobile install would benefit from MORE VOLTAGE before it would benefit from higher current ability. ? So obviously I beefed up the wiring from the front to the back.? This stereo wiring is ?¡± across the copper.? Man this is serious stuff¡? Plus how do we increase the voltage on the system?? I used to DRAG RACE CARS and we had the same problem.? Without an alternator we¡¯d have to charge the battery between rounds.? The battery people came up with a special battery, a 16 Volt one with a 12 volt tap.? The Starter would run on the 16 volts and the electronics would run on 12.? It required an 18V plus battery charger to charge the battery. ? ? Maybe you need to find one of these high end mobile car stereo shops like what we have here.? These guys are next door to my wife¡¯s place of employment.? So I pop in every now and then.? Well they have all the fancy kits to BEEF up almost every kind of vehicle with more power.? Maybe there is a special DUAL ALTERNATOR kit for your vehicle?? Or maybe a special few hundred amp job?? Of course you pay them to do the work and you don¡¯t even get your hands dirty. ? This is a new truck here for me now and I will be adding all sorts of stuff¡? What if a guy was to use a specially built ADDITIONAL alternator (16 V or even 24V) and then had a special battery box in the rear of batteries like my 16 volt ones or a pair of your mondo Trojan units in a 24 V config.? Then either a 24 volt transistor or 50 volt for that matter¡? or a 12 volt running on 16 volts could generate more power. ? Of course, I also have the 5KW generator and have already discussed running the gen and powering the amp.? At that point it could be any voltage amplifier. ? Both work¡? Its just seriously getting the voltage up that matters.? This really starts becoming critical as you pass that 1KW level. ? BOB ? From:
ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of PA3DUV ? Bob, ? I tried the caps some years ago when I ran a single 500 watt SGC amplifier.. Yes they work, but only at very short bursts. With the two Henry SS750 amps @ 1 kW out each I had to ask myself: where does the power come from. Upgrading the alternator is not possible, the cab forward design of my 2006 Toyota has eaten all space in the engine compartment.?There is no way I could fit two 200 amp alternators without major surgery. So that leaves the 5 kW Honda genset on a bike rack or 2 hefty 150 pound AMG batteries as the only alternative. ? Cheers, Dick PA3DUV ? ? ?
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