-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
New Amp Install (picture heavy)
- Thread starter fogdog
- Start date
My complaint, if any, would be to ditch the para dynamics low pass filter, and put a nice drake filter in line, or if you can find a bencher low pass. Those para dynamics things are built so poorly, I would have for something in it to go bad, and before you know it, you kill your amplifier because of a short, or loose solder joint. Worst case scenario, try this: LOW PASS FILTER
And that would still be 100 times better than what you are doing now.
That, plus some good Belden RG-8X or LMR240 for your jumpers, and good Amphenol connectors at the least, and some LMR240 going to your antenna. It will all handle the power output without loss in heat, although in mobile lead lengths of a few feet, loss is negligible, but just knowing it will handle the power and you have good connections keeps peace of mind that everything is "right".
And that would still be 100 times better than what you are doing now.
That, plus some good Belden RG-8X or LMR240 for your jumpers, and good Amphenol connectors at the least, and some LMR240 going to your antenna. It will all handle the power output without loss in heat, although in mobile lead lengths of a few feet, loss is negligible, but just knowing it will handle the power and you have good connections keeps peace of mind that everything is "right".
Well I put it in cuz the wifes likes to listen to her radio while she cooks, or puzzles, and I like to eat, and the radio being so close to the kitchen was causing serious bleed over. Happy Wife happy life! In an attempt to cure this I installed this filter. Which didn't do anything, but for some reason it lowers my swr a bit, so why not.? my pickup is my Shack lol! I just drive the truck down our road a bit, and it's all good.
73
73
The coax is quality RG-8X, with and soldered Mil-spec connectors. As for the filter, I'm not worried at all. It's been in the truck for a good while.
It didn't match your antenna any better, it just attenuated the reflect back to the meter making it appear to have lowered your swr. That's my guess having never used one.
Nice neat install but you have broken Rule #1 which is a cardinal DO NOT DO
Never ever wire directly to the battery negative terminal. It is a seriously bad idea. Apart from ground loops, if for some reason there's a fault with the main battery ground to body strap such as it breaking, becoming loose or the connection at the body becoming corroded and high resistance, because your radio gear is electrically connected to the body through the antenna and any brackets screwed to the vehicle through metal, absolutely everything that uses the body of the vehicle as a ground connection will have the full current of that device flowing through your radio as a path back to 0V. That includes things like lights, the engine management system, the starter motor. You could end up with hundreds of amps flowing through your radio and amp.
You want to connect the ground wires for the radio and amp to the car body near where the thick ground strap from the battery connects to the body.
More here.
Grounding Negative System
With that out of the way you'll benefit massively from doing some bonding of the hood across the hinge from the hood to the body and do the same for the tailgate as well, especially if you've got the antenna mounted there. You should find that when you've done it you'll need to shorten the antenna as the resonant point will have dropped. That is good because it means you're making the RF path over the body of the vehicle, and therefore the ground plane, more efficient which means better signal radiated and received.
Never ever wire directly to the battery negative terminal. It is a seriously bad idea. Apart from ground loops, if for some reason there's a fault with the main battery ground to body strap such as it breaking, becoming loose or the connection at the body becoming corroded and high resistance, because your radio gear is electrically connected to the body through the antenna and any brackets screwed to the vehicle through metal, absolutely everything that uses the body of the vehicle as a ground connection will have the full current of that device flowing through your radio as a path back to 0V. That includes things like lights, the engine management system, the starter motor. You could end up with hundreds of amps flowing through your radio and amp.
You want to connect the ground wires for the radio and amp to the car body near where the thick ground strap from the battery connects to the body.
More here.
Grounding Negative System
With that out of the way you'll benefit massively from doing some bonding of the hood across the hinge from the hood to the body and do the same for the tailgate as well, especially if you've got the antenna mounted there. You should find that when you've done it you'll need to shorten the antenna as the resonant point will have dropped. That is good because it means you're making the RF path over the body of the vehicle, and therefore the ground plane, more efficient which means better signal radiated and received.
Dont know why they tell people to do that, grounds should always be as short as possibe, read the article that M0GVZ posted, it really has some good info in it. And about your swr issue, try different jumper lengths from the radio to the amp, and amp to radio, you may have to try several combinations until you get it right. Had the same issue. Sometimes mobile installs can be a pain. Good luck and hope you get it all resolved. God bless and 73 's.
Thanks, yeah I have been trying different jumpers. Truck is grounded and bonded in a bunch of places. I did get the SWR from over 2.1.1 to 1.1.1 when I got the 10k antenna, so I did my work there. This amp is is making me look for new ideas.
Yeah, my 10K was waaaaay long. Can't remember how much I chopped off, but I remember thinking it was a lot. Bought cheap bolt cutters at Harbor Freight, which made it a breeze.
I would recommend shortening your ground, as others have mentioned. I did mine right where the seat bolts, as was also mentioned.
Nice clean install, and should make for a fun mobile shack.
73,
RT307
While I agree with you, have you had a good look at some of the modern vehicles grounding straps??
On my old GMC I had to replace at the factory straps going from engine to frame as they were shit from the factory and didn't like my TS 500.
I've tried a bunch of different combinations of coax lengths with no success. I guess I should just buy 150' of copper flat strap and bond and ground the hell out of everything on the truck.
I did get on the radio about an hour ago, and I was the guy that everyone was calling for. That has never happened. I mean I couldn't keep up. It was good. I had a few longer qso's with some operators that said this thing sounds crystal clear, and I broke through over everybody out there. I guess I'm on to something. Just hope I can get that dang swr down. :bdh:
73
I did get on the radio about an hour ago, and I was the guy that everyone was calling for. That has never happened. I mean I couldn't keep up. It was good. I had a few longer qso's with some operators that said this thing sounds crystal clear, and I broke through over everybody out there. I guess I'm on to something. Just hope I can get that dang swr down. :bdh:
73
Maybe changing the grounding point from the battery to a different point may help. Also ground the chassis of the amp itself. May help with the swr readings. I know til will get it sorted. Just throwing some ideas out there that might help. Good luck and god bless. And sounds like you are already having success with it. Keep it up man. Good deal.