| Author |
Message |
    
Blewz4u
New member
Username: Blewz4u
Post Number: 1
Registered: 11-2004
| | Posted on Thursday, January 27, 2005 - 8:50 pm: | 
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Here's the idea. I have 2 Black Cat HD300 solid state mobile amps. I'd like to run the output of either a Magnum 257 or an Emperor TS-5010 into a splitter or co-phase harness, then into each of the amps. From the Black Cats, then into two seperate Astatic 1K antennas, mounted on the roof rack of my 2004 Honda CR-V.
I've done the math, either there is going to be a gain of 600 watts ERP off the antennas or there will be enough RF feedback to blow something.
I open the floor to all ideas and feedback.
Thank you |
Chad
Intermediate Member
Username: Chad
Post Number: 112
Registered: 11-2004
| | Posted on Friday, January 28, 2005 - 8:43 am: |
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The CRV is not wide enough for co-phase antennas to work properly, unless you want to blow sideways  One great antenna and one amp will probably get you what you need. Best luck! |
Blewz4u
New member
Username: Blewz4u
Post Number: 3
Registered: 11-2004
| | Posted on Saturday, January 29, 2005 - 2:34 pm: |
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Chad, you're right about that. But I'd still like to try the experiment. I'll just use my big old work truck. Curiosity has the best of me. |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 183
Registered: 9-2004
| | Posted on Saturday, January 29, 2005 - 3:48 pm: |
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the CB'er mentality lives on! if one amp is good then two oughtta really blow some smoke!!!
seems like a great idea but, cophase harnesses use 75ohm coax, not the best match for the input of an amp.
there is not a passenger vehicle on the road today that is wide enough for co phased antennas. the reason i know this is becaouse of the law that states that a vehicle being sold in this country must be able to fit into a lane of traffic on any city, county, or state maintained road. most lanes of traffic in rural areas are 102" wide, the exact distance where a cophased antenna system will begin to work properly. just because someone came up with an idea, doesnt mean its a good one. co phasing antennas is a marketing ploy to sell twice as many antennas. (pretty brilliat huh!) and they prey upon the easiest targets: truckers. J/K! dont flame me!
i think the reason most people like them is that they "look cool", and add symmetry to an otherwise lopsided vehiclular accessory.
matt
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Blewz4u
New member
Username: Blewz4u
Post Number: 4
Registered: 11-2004
| | Posted on Saturday, January 29, 2005 - 9:32 pm: |
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Wasn't there some sort of 65% height / distance rule for "loaded antennas" or maybe that was some manufacturers hype I'm remembering. Either way, distance between antennas (for this experiment) is not a problem on the big truck. I'm not considering a permanent installation, only a test of the theory. It's true about the co-phase harness and 75 ohms. I don't see how that would be healthy for the amplifiers. I could use a splitter, or build a shielded junction box / splitter for minimal RF loss. What are your thoughts? |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 190
Registered: 9-2004
| | Posted on Sunday, January 30, 2005 - 3:59 pm: |
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this is just my opinion, but i think that in order for this to work, the two amplifiers would have to have EXACTLY the same input and output impedences. i seriously doubt that any two amplifiers are exactly the same. this is why they sell matched pairs of transistors. we know that electricity will follow the path of least resistance and the mismatch could be a problem. it seems to me that there are a lot of reasons that this wont work that im not aware of. if it did work, there would be lots of info about it on the net.
matt |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 191
Registered: 9-2004
| | Posted on Sunday, January 30, 2005 - 4:08 pm: |
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wait! ive got the plan!
you need to get two radios, two amps, and two antennas. hook it all up in the car, hold one mic in each hand, and if you key them up at the same time, you wont blow the front end in the radios! yeah, this should be pretty cool!LOL
matt |
Supertech1
Junior Member
Username: Supertech1
Post Number: 15
Registered: 1-2005
| | Posted on Tuesday, February 01, 2005 - 11:55 pm: |
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I got A solution---1 radio, 1 hybrid splitter, 2 antenna tuners(low power, to match and balance the outputs to the inputs on each of the 2 amps), 1 hybrid combiner(high power), co-phase(harness) to 2 antennas @102" seperation-----whala!!--- or......just trade those two amps in for a 4 pill and four-get-about-it!!
LOL!!!!!!!!!
supertech |
Patzerozero
Intermediate Member
Username: Patzerozero
Post Number: 398
Registered: 7-2004
| | Posted on Wednesday, February 02, 2005 - 5:23 pm: |
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no need for debate here, this is a very basic, rough view of the matter. if you assume ALL solid state amps are 2 pill, a 4 pill is already 2-2 pills with a combiner, and an 8 is 2 more 2 pills with combiners, etc.
the builder already did all the work for you, and put it in 1 housing, to boot! |
Supertech1
Junior Member
Username: Supertech1
Post Number: 16
Registered: 1-2005
| | Posted on Wednesday, February 02, 2005 - 6:40 pm: |
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THAT'S what I'M talkin' about!!!!
--AND...1 or 2 driving 8(m4v or m1200) is a 1 or 2 pill driver 'split' 4 ways driving 4 banks of 2..recombined to 1 output. It stands to reason that it can all be done with 1 modulator and 4 identical(matched) 2 pill amps..enclose all your splitters and combiner in seperate boxes with so239 connectors and a whole lot of patch cords. let's take this a step further and have fine tuning adjustment on each leg of the splitter/combiner channel for balancing/ equilizing the 'mix'.
The only problem I can see with this set-up is way too many key-up relays and circuits and the recieve path would be severly degraded. solution for that would be---all amps wired through and active(no internal key-up circuit) and to install dc power control relays in all the amps triggered from a common external tx/rx relay so that the rf recieve path bypasses this 'nightmare' when you are unkeyed.
This set-up may sound crazy but think about this...if you blow a pill, you just need to service the amp that failed instead of the 1 big amp--(less risk to the remaining amps) and if you were smart about it, you would have 1 or 2 spare amps to swap out the bad one which can be repaired seperately....hence NO DOWN TIME!!
LOL----just a thought(more like a seizure!!)
***TUNE FOR MAXIMUM SMOKE***
supertech |
Patzerozero
Intermediate Member
Username: Patzerozero
Post Number: 405
Registered: 7-2004
| | Posted on Thursday, February 03, 2005 - 4:44 pm: |
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"***TUNE FOR MAXIMUM SMOKE***"
my thoughts exactly |
Bullet
Intermediate Member
Username: Bullet
Post Number: 374
Registered: 7-2003
| | Posted on Wednesday, February 16, 2005 - 4:07 am: |
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why not just go with a nice single tube amp that is in the watt range your looking for.
you can even use tetrodes for thier low wattage drive caractoristics for radio drive use, cuts the cost of a driver amp.
thiers a few ways to set up for ac in mobiles
look into it and see that ya think. |
Bluegrass
Intermediate Member
Username: Bluegrass
Post Number: 224
Registered: 12-2004
| | Posted on Wednesday, March 16, 2005 - 8:06 am: |
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Yeah this is something i've been thinking about for a while.Take two amps co-phase them but connect them to one antenna.That should really get out. |
Allan
Intermediate Member
Username: Allan
Post Number: 122
Registered: 2-2006
| | Posted on Friday, May 05, 2006 - 6:51 pm: |
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It needs to be in stereo, tho. Maybe if one could wire up C-quam AM Stereo, like Motorola came out with for AM broadcasting in the '80's, into the signal with a good 10khz bandwidth, then they'd have something bodatious. Sad, but i doubt any rig out there could tell the diff having only one speaker and all ....... |
Georgeodjungle
Member
Username: Georgeodjungle
Post Number: 87
Registered: 1-2006
| | Posted on Friday, May 05, 2006 - 8:42 pm: |
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2 amps on 2 antennas with out combinding
no worky varry well.
you only have to get close.
matched sets of pills is lame.
there's nothing matched where they go.
1st into not precision home made looking transformer.
& not rap evenly
then 10%resistors
10% caps
& out to another xtfmr.
nothing balanced there.
any ways.
the 2 receive amps must be on or off not one on & off
i think it's a timming thing again.
this is working out pretty cool. |
Wolverine
Advanced Member
Username: Wolverine
Post Number: 634
Registered: 2-2003
| | Posted on Saturday, May 06, 2006 - 3:36 am: |
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OMG, LOL, ROTF, you guys are killing me. "Tune for maximum smoke", yeah, that's the ticket.
Wolverine. |
Georgeodjungle
Member
Username: Georgeodjungle
Post Number: 89
Registered: 1-2006
| | Posted on Saturday, May 06, 2006 - 12:08 pm: |
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o.k. mr negative:
ya that round thing "wheel" will never work. |
