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Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 225
Registered: 4-2005
| | Posted on Thursday, September 22, 2005 - 4:26 pm: | 
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I don't wanna tell you all what I GAVE UP for this amp but DID in fact hear a friend talk on it the day before I took possesion..
Amp in question (soon to be in garbage) is a Near new mint TNT 400. SWRs after hooking up amp in Jeep are 5:1!! My barefoot readings a 1:2-1:3 TOPS. Powers up fine..Preamp works great and am feeding it from the battery with 6g heavy machine wire. A 30a circut breaker is at the battery while 2 35a fuses are in line at the amp. Ground is no more than 9" and goes to bolt at seat/body bolt...metal sanded and wire brushed to BARE contact...OHMed to be sure of POSITIVE grounding.
Bought a NEW SWR meter to be sure I was not being misled...all true.
Moved unit to base and tried it on my 25a power supply just to DK and take SWR reading....through the roof while again barefoot is 1:4.
What could have gone wrong with this amp in transit? Am I overlooking something stupid? I don't think so...pretty straight forward.
I found one bad ground/solder joint at the "transiever" side SO-259...repaired to no avail...I'm pretty livid right now...what might I look for other than a refund?
THANKS!
HANK CEF559
BTW...Galaxy Pluto DK3w or Grant XL DK2.5w were both tried and NEVER once modulated into amp. |
Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 226
Registered: 4-2005
| | Posted on Thursday, September 22, 2005 - 9:00 pm: |
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Alright...update...Friend came over and we switched amps from his vehicle to mine. Same exact amp....dropped his that I SAW work into my Jeep and had same problem. Put Mine into his van and after a little VR power adjustment on his S9 he had 1.3SWR! I'm doing something wrong!
We pulled his car next to my Jeep just to attach his coax and antenna and still had over 3:1 SWR with his antenna system.
We can now rule out the Amp itself or antenna system itself...any ideas?
I'll be working on this one! I'll keep you all updated as we go.
ONE other thing...I noticed more than a few times the "key up" relay sticking in my vehicle but not in his AT ALL? I'm I to think I'm not providing enough DK? Too Much? Not enough Amps? Perhaps (and I know I shouldn't even think this) the 12v feed wire from the battery is TOO big?
Hmmmmm...at least no amps were harmed in this installation.
I told you all that it happened with either of my radios SO I have to assume its a DK issue.
Losing sleep over here~ |
Nobodyknows
Intermediate Member
Username: Nobodyknows
Post Number: 104
Registered: 4-2005
| | Posted on Thursday, September 22, 2005 - 10:34 pm: |
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Although I don't run as much power as that one does by far, I wonder about something you said. You grounded it to the bolt on the seat, ok, The chasis sits on rubber bushings though. Is the chasis directly attached thru heavy cable to the neg side of the battery? Or is the chasis grounded to the motor via whimpy ground strap?
No matter the wattage wasteful or not i'd go direct to the battery with pos and neg. Also try it without that circuit breaker inline.
Where is your antenna mounted? what kind? and what coax? Extra ground from the amp and radio to a good ground? Extra ground straps from the chasis to the frame? Also, On this friends van where was his antenna mounted and what kind? |
Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 229
Registered: 4-2005
| | Posted on Friday, September 23, 2005 - 5:12 pm: |
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Good questions but let me submit this first...what are the possibilities that this is a High drive amp? How can I tell? Like I said my buddy runs this amp with between 1.5 to 3w DK and gets great SWRs and talks real well.
As I TRY to tune the radio to the amp I watch the SWRs drop like a STONE when I increase the DK power. ?????? If I run 8-10w DK into the amp I get great SWRs on all three modes. (Hi-Med-Lo)
On "HI" with good SWRs it'll DK just shy of 200w and swing to 300+w. Hard to read the "weenie" size meter accurately...sorry.
The more I lower the DK the worse they get. Right now the DK is set at 4.5w (safety zone?)and I get readings of 1:4 on "HI"...2:1 on "MED" and 2:5 on "LO".
If I raise the DK to 8wI get below 1:5 across the board.
Something to think about?
Amp has 4 MFR492's...could it be it needs the Hi drive in my application and my friend is getting lucky? Amp does get hot but I'm dealing with less than perfect SWRs and no fan aboard..yet.
Also when the DK is low the "key up" sticks remember? I raise power and that goes away entirely.
Anyway..nobodyknows..to answer your questions.
1) Battery ground is grounded to fender...I could run yet another ground to chassis and see how that does. I did run ground also last night to the amp straight from the battery with my jumper cable....no change. Something to remember also....same problem in BASE with nothing the same except the radio(s)/amp and jumpers...
2) bypassed the circut breaker earlier today...that was on my checklist..
3)just got done setting up the grant out there and ran another 6" braid ground from radio and another from amp to previous ground station.
4) buddy has 3ft silverload on R/R corner of van about 1ft below the roofline..RG8X
Mine is a Wilson2000 trucker on roof and about 2ft from rear of Cherokee..also mini8 coax.
Although I've tried all my jumpers doesn't mean they are ALL good...I could try making up a few new 3fters but I don't have high hopes about that!
Great questions though...thanks for your time!
Really feeling like this is a high driver and I'm not feeding enough wattage. I'm chasing ghosts in the Jeep if the base station has the same problem with this equipment.
HELP! I wanna TALK!
Hank |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1521
Registered: 7-2004
| | Posted on Friday, September 23, 2005 - 6:18 pm: |
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the 'relay sticking'-ESPECIALLY in YOUR vehicle BUT NOT his is a sure sign of 'high reflect'. if your swr's are good without the amp inline AT ALL, but things do not work right once inline, the problem is somewhere in the jumper(s) and/or amp/coax/antenna of YOUR vehicle. the HIGH input you're FORCING thru the amp is FORCING the relay to work & faking the swr improvement. i'll bet if you checked on a reflect-meter, you'll see reflect AT LEAST HALF if not MORE, then the measured output-NOT GOOD! also stressing the amp under increased SWR condition.
i know it can work, but i just don't like the crappy rg58 that comes on mag mounts, that created all kinds of hassles in my durango the 1st time i put a 1 pill in it to go on a trip. is this the most wattage you've tried on your current antenna/mount/coax? you say it works fine on your buddies set up, but not yours. antenna location can also change things with mag mount/reflect issues.
if you plan on getting serious with mobile installation-even if only running modest power, my suggestion is to immediately upgrade mount & coax. as long as wilson 2k has not been compromised in any way, it should work fine. sometimes tons of added groung cables exacerbate problems, rather then helping. i also went to palstar wm150m meter with remote unit to eliminate 1 very long jumper. |
Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 230
Registered: 4-2005
| | Posted on Saturday, September 24, 2005 - 10:24 am: |
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Thanks Pat...Let me clarify
*DID not work good when we hooked MY system to buddies coax and antenna.
*Currently using Grant tuned down to 1.5w DK (so low I can no longer register SWR Cal to check barefoot swr) This tune works best with amp on HI pwr and is giving me 1:5 SWR...DK75 swing 300w.
*I'll be testing and tuning more today...I'll use my base MFJ to check reflected Pwr as suggested. It was WAY more than Fwd power before...so I know EXACTLY what your saying.
* For what its worth..the wilson2000 trucker is hard mounted to a steel bracket screwed to the luggage rack on the roof.No mag mount or RG58 involved...all mini8 stuff including jumpers.
It has been further grounded with a few short jumpers but did OHm out well before all that. If I thought it would be a WHOLE lot better to hard mount the thing THROUGH my roof I would do it. Just rather not If this wouldn't make a difference.
Thanks Working between kids over here! |
Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 234
Registered: 4-2005
| | Posted on Saturday, September 24, 2005 - 2:09 pm: |
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More testing and tuning using MFJ antenna tuner in bypass mode. I was able to tune the Grant to a 2.5DK 15pep which now allows me to check barefoot SWR....FLAT to maybe 1:2 when modulating. Very little reflected power showing. This test done with AMP inline but NOT "on".
Throw the switch...reflected power showing more than forward power on this meter and SWRs are off the scale.... too high too read on the cross sweep meter.
Switch back to new ratshack meter:
I can get it to show 1:4swr and by switching to power mode I see 75DK swing to the 300area.
SOooooo confused!
Once again..great SWRs until amp is on...then a lot comes back reflected....GOTTA be my jumpers if it does it in the base as well.
REALLY seeming like its not worth the headache at this point.
Pat.."if I want to get serious?" Wanna know how serious I am about doing this right?
I traded the S-9 for this amp..well I got the amp and $100 but I want the S-9 back!
Thinking hardmount through the roof right now...although maybe I can borrow a friends wilson 1000 mag mount to test first.
Thought this was supposed to be easy?
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Dd18
Member
Username: Dd18
Post Number: 56
Registered: 11-2004
| | Posted on Saturday, September 24, 2005 - 2:41 pm: |
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I had exactly the same problem with a DX500 and wilson 5k in my car.
Here is how I fixed it. (in order of importance)
1. Earth the coax braid/antenna ground at the antenna to the vehicle. Shorter and bigger the wire/braid the better.
2. Earth the Amp to the chasis as above. Drill a hole and fit a bolt washer and nut to ensure a good connection. Seat mounts are usually good earths.
3. Make sure negative side of Battery is earthed with short lead as above.
That was all it took.....
Good luck. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1527
Registered: 7-2004
| | Posted on Saturday, September 24, 2005 - 4:13 pm: |
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OUCH
the only way to resolve a situation is to admit you have a problem . if getting the S9 back is not an option...
if the amp worked IN your buddies vehicle, correctly, then you know the problem is with YOUR end...obviously, reflected power showing MORE then forward power is NOT a good thing.
try going with 6' jumpers from radio to amp & amp to meter. make sure coax from antenna, if real long, is not coiled up, but route it around the inside of the truck. it's possible antenna is bad-4 watts is ok, but HIGH POWER shorts coil. could be antenna location, mount, etc. my factory aluminum luggage racks' mounting screws ohm out to ZERO when checked to battery ground, yet rack itself DOES NOT unless you scrape through the coating in some spots. are you using pl259 at mount/antenna end of coax, or lugs on shield & center conductor? i removed the pl259 ball mount from my triple mag mount & replaced it with predator mount & used lugs-that alone stopped SRWs from 'moving' while truck was in motion.
i run considerably more then that amp through a magnet mount with NO problems, & there is a durango in NJ running 21 x 2879's on leece-nevilles @ 20 volts(1500 key, 3kw+ swing) through the same mag mount i'm using...drilling holes may be the preferred method, but have you ever heard my truck get out with a mag-mount? |
Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 235
Registered: 4-2005
| | Posted on Sunday, September 25, 2005 - 9:43 am: |
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All good Shuff here. Dd18 thanks for the input. All you mentioned was done with the install. I've replaced the ground wires with 6" braided strap. Right now the antenna coax is out...was testing yesterday and saw too much flucuation in meter. The more I shook the antenna coax the more it made a difference in the meters and in receive!
Ripped it out and chopped it into pieces to be SURE I'd get fresh stuff. Soldered up another 18' length and have yet to install it. I needed a little time away from this annoyance. Problem is amplified 10X when you only get 1/2hr at a clip to work/think until one of 3 kids or the wife "needs" something. Especially getting used to the wifes evil eye from the front door
Pat..as a matter of course I will build a 3 or 4 5" mag mount this week..been wanting to do that anyway. The problem you described with the antenna going down with the juice on has crossed my mind as well as the RG8 I'm replaceing now. Its less than a year old but had a few good kinks I found due to running under the back seat.
In time,through process of elimination I'll get this stuff sorted out and operating as close to 100% efficiency as possible...I'll settle for nothing less. If it's supposed to work on 3 power levels...it WILL!
You asked about my antenna mount. The one I'm using IS old and is the 3/8-24 / pl-259 "through the roof" style....like wilson sells...forgot where I bought it YEARS AGO. It is mounted through a 1/4" steel plate which is screwed into the aluminum rack. Short ground straps tie the mount to the rack / rack to body...your right...magnet mount may be better.
I would try another one of my antennas like the 5.5' Frances but none are tunable and SWRS are high....gives me more reason to look into another mounting system huh?
The S-9 problem is easily resolved |
Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 238
Registered: 4-2005
| | Posted on Sunday, September 25, 2005 - 2:22 pm: |
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Note to self:
Upon setting up linear DO NOT touch PL259's OR metal case dosy meter while keying up...wanna see scars? |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1538
Registered: 7-2004
| | Posted on Sunday, September 25, 2005 - 7:14 pm: |
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GROUND...if you were using a metallic cased mic, such as an old d104m-type, you'd experience what is affectionately known as 'mic-bite'. you don't always feel it through the fingers, but it's an odd feeling to describe when you touch your lip to the metallic screen.
if you go to the website i mentioned, i believe you can go through the catalog pages & read an article on poor grounding/mic bite. it's base-oriented, but he explains what can happen with too many grounds not doing the proper job.
oh yeah, did i say that grounding is still an issue? |
Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 241
Registered: 4-2005
| | Posted on Thursday, September 29, 2005 - 2:28 pm: |
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OK all seems well...chalk it up to a newbie amp user...never realized the radio needed to be tuned to the amp. I Knew I had to stay below 4w DK and see what worked best but never realized how much it can change SWR in a mobile installation.
AS OF RIGHT NOW:
Grant XL DK 2.5w.. swing to 10 = 130DK... swing to 300+w on TNT 400 ("HI" setting). SWR with amp on is "SET" at 1:3.1
I had to sacrafice a little swing for SWR sake and the power mic to avoid a little sqeal/feedback hum...small price to pay
Will stay as is UNTIL I work out an new antenna system. Was considering a 10K but after seeing one UP COSE I think my Jeep would flop onto its side if I turn too fast...."Thang" is BIG!
Thanks again for all input~
Hank '905 |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1560
Registered: 7-2004
| | Posted on Thursday, September 29, 2005 - 8:40 pm: |
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