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Help, my first Ham Radio installation advice/question?

leeshuming

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New Ham operator here.
I just received my first mobile radio and I am in the middle of installing it.

I was going to wire both the positive and negative leads directly to battery with the supplied wiring kit from the radio, but realized the supplied wires are not long enough.

So rather than making a new set of wires, I have since decided to wire my positive lead to the in-cabin Aux 2 and have the possibility to use my radio even when my engine is off.
I understand that Aux 2 already has a built-in 40A fuse, but I am going to connect the positive wire with the 15amp that is already wired as a another layer of protection.

Now here are my questions:

1) Which is a better location to ground my negative wire to the chassis? I see only 2 options: option a) to the bolt that is below the passenger seat near the center console? Or option b) to one of the 3 grounding bolts that is inside the panel of the passenger footwell near the door harness? Or it doesn't matter?

2) this is more important, do I really need to use the built-in 15amp fuse on the negative leads? Can I cut it? Or do I really need it? I mean in the event where the fuse of my negative lead pops, I would no longer have a ground and all the current would then hit and fry my radio?

Please advise,

Tks
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lashlee

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If I remember correctly, two of the aux switches are 15a, and two are 40a. I would use the 15a options just so that you can save the 40a for something beefy.

As to your questions:

1) either ground will work. Use whichever one is easier.

2) No, you don't need the fuse if you use one of the aux switches. I would leave the fuse since it doesn't hurt to have an additional fuse.
 
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leeshuming

leeshuming

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Tks. Good to know.

I need to use one of the 40a Aux switches because I have already used the other 15A switches.

I guess I will remove the fuse on the negative lead, as I have to trim some wires to make them shorter. Tks again.
 

SOTA

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Tks. Good to know.

I need to use one of the 40a Aux switches because I have already used the other 15A switches.

I guess I will remove the fuse on the negative lead, as I have to trim some wires to make them shorter. Tks again.
Short answer, leave the negative fuse.

Slightly longer :

The pictorial at right is courtesy of the ARRL. It clearly represents the correct wiring scenario, whereas the negative lead goes to the same chassis grounding point as the battery's chassis ground point. And as shown, the negative lead fuse should not be removed. The reason is, if the grounding point should lose its integrity, excessive current could flow through the transceiver's negative lead.

Reference page with the pictorial which is worth reading in it’s entirety but too long for most people :

http://www.k0bg.com/wiring.html

73,

Joe
 

jeepoch

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@leeshuming

One pretty minor point is that a vehicle ground is not a good earth ground due to the rubber insulation of the tires. The reason the power leads are recommended to be connected directly to the battery is that while the vehicle body (frame) is common, it's only common to the vehicle.

Relative to Earth, the vehicle is still nonetheless electrically isolated. So as the vehicle moves around it's picking up stray charges and acting like a very large capacitor. The point of contact of your wiring's distance to the battery is a conduit which also acts as an antenna relative to the various frequencies at whatever impedance is presented on the overall circuit with respect to the Earth.

Unfortunately this can introduce input noise on the supplied power. Very good radios provide a decent amount of filtering, and signal conditioning which mitigates this noise. But as the old adage goes - "garbage in, garbage out". Any unfiltered input noise is coupled into nearly every receiver and transmitter circuit.

So depending on your end result, how paranoid or OCD you are, a direct connection to the battery will always be your absolute best possible wiring option. That's why it is recommended best practice. And even though the power wires themselves can also act as an antenna for exactly the same reasons, it's surface area is so much smaller than your vehicle's body.

A splice to make the wires longer, is such a better solution than cutting a shorter wire and using the vehicle's body. Also recall, that the impedance of a true DC circuit is practically zero.

Of course, many other factors also affect the operation of your station. Such as matching transmission line and antenna impedance (minimizing SWR), effective ground plane and antenna gain, the power supply wiring may be the least of your things to lose sleep over.

73
Jay
 

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I concur that you should extend the wires. Solder them and shrink wrap them with adhesive-based shrink tubing and you will never worry about them again. Go straight to the battery with both positive and negative. Use a very good quality antenna cable and antenna. Be careful routing your antenna cable. Keep it away from as much wiring as possible. Not sure if you have an antenna yet, but get one where you can adjust the impedance so you can get as low and SWR as possible, again at the others pointed out.
 

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What has been said above is the correct and best way. That being said I hooked up my yaesu 2750 to Aux 1 and used the ground near the console. It has so far worked for me. I have been able to reach some pretty distant repeaters without being told I sound too bad. Really just depends on your situation And use case. Power is part of the equation but your antenna has a lot to do with it as well.
 

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[use Aux switch 2 in order to] have the possibility to use my radio even when my engine is off.
Lots of input already, but.... you know if you connect direct to battery, you'll *already* be able to use the radio whether or not the vehicle is on, right? Conversely, you'll need to make sure to turn it off when leaving the vehicle, in order to avoid draining the battery.
 

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I did exactly the same thing but used a 15amp aux switch. No issues whatsoever with clean power. Clipped the negative fuse and hit battery for grounding, although I’m sure you’d probably be fine with chasis ground if you’d like to try using the aux wires in the passenger foot well. I ran mine to the engine bay to be safe (#1 if it introduced noise I could go directly to battery this way and #2 I could free up an aux switch in the future if I needed too) but if I had to do it again I’d go straight off the aux in the foot well and hit the chasis ground there as well.

Welcome to the hobby!

73
K5WJL

yes my vanity is a nod to my Jeep 😂
 
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leeshuming

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Thank you all for your input.
I have already purchased my antenna and coax cable.

I purchased the antenna, Super Elastic Signal Stick from Signal Stuff and the Topsy NMO mount (bundle). (I cannot really install a tall antenna due to the clearance issue with my garage).

I am installing the antenna on the driver's front of my jeep and wire the coax cable through the hole on the firewall.. (see photo)

Honestly, because I have a 4xe, and my Jeep already has too many extra wires that a regular ICE doesn't have. I am a bit worried if there would be interference. I rarely see any post with 4xe owners installing a ham here.

Anyway, I am installing my radio under the driver's seat, (I already have an ARB compressor under the passenger side).. wire the positive and negative leads to the footwell of the passenger and connect to Aux 2, with the original 15A fuse and the negative to the sidewall bolt near the door (at the footwell) without the fuse.

I have also tested with a multimeter and found that I could actually this bolt (under the carpet and the center control..) well at least there is a 12V current.. but unsure whether it is safe. (See photo pls).

Regardless, I will test this setup first and see how it goes, especially that I am a new ham, I am not worried about screwing up (as long as my jeep doesn't burn).. I need to learn knowledge through all kinds of experiences.

I mean, because I have already hardwired my winch, dometic fridge and powersteps to my 12V battery, I am thinking perhaps it would be better to either install a dual battery system under the hood, or a redarc type of system in the rear and power my radio from the back.

I mean I feel like I am stressing my 12V battery.. btw it is not stock, I have already upgraded to an odyssey.

Thank you all.

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SOTA

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Honestly, because I have a 4xe, and my Jeep already has too many extra wires that a regular ICE doesn't have. I am a bit worried if there would be interference. I rarely see any post with 4xe owners installing a ham here.

Anyway, I am installing my radio under the driver's seat, (I already have an ARB compressor under the passenger side).. wire the positive and negative leads to the footwell of the passenger and connect to Aux 2, with the original 15A fuse and the negative to the sidewall bolt near the door (at the footwell) without the fuse.

I have also tested with a multimeter and found that I could actually this bolt (under the carpet and the center control..) well at least there is a 12V current.. but unsure whether it is safe. (See photo pls).

Regardless, I will test this setup first and see how it goes, especially that I am a new ham, I am not worried about screwing up (as long as my jeep doesn't burn).. I need to learn knowledge through all kinds of experiences.

I mean I feel like I am stressing my 12V battery.. btw it is not stock, I have already upgraded to an odyssey.
Having installed ham radios in my vehicles since the 70’s and dealing with all kinds of issues let me share my unconventional solution that I’ve been using for the last decade.

I just use a separate battery that only powers my ham rigs with a very short power lead to minimize RFI pickup. You do need to charge the battery periodically, preferably while you are driving with the engine running. Or you could charge it in your house every few weeks or so. I charge mine with Solar since I’m such a nerd 😎.

Back in the lead acid days this was not as convenient but now a LiFePO4 battery is so much lighter, smaller and cheaper considering depth of discharge and 10 year lifespan I use them exclusively. One would probably fit under the seat next to your radio.

There are small charging differences and you have to be sure your radio can handle the slightly higher voltage but it’s rarely a problem. Most radios have better transmit IMD specs at a higher voltage as a bonus.

Given your concerns listed above this might be a solution worth considering.

Let me know if you need more info to pursue this or you will likely be fine with your original plan but I still say keep the negative fuse.

The radio MFR put it there in accordance with the ARRL advice linked above.
 
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leeshuming

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Having installed ham radios in my vehicles since the 70’s and dealing with all kinds of issues let me share my unconventional solution that I’ve been using for the last decade.

I just use a separate battery that only powers my ham rigs with a very short power lead to minimize RFI pickup. You do need to charge the battery periodically, preferably while you are driving with the engine running.

Back in the lead acid days this was not as convenient but now a LiFePO4 battery is so much lighter, smaller and cheaper considering depth of discharge and 10 year lifespan I use them exclusively. One would probably fit under the seat next to your radio.

There are small charging differences and you have to be sure your radio can handle the slightly higher voltage but it’s rarely a problem. Most radios have better transmit IMD specs at a higher voltage as a bonus.

Given your concerns listed above this might be a solution worth considering.

Let me know if you need more info to pursue this or you will likely be fine with your original plan but I still say keep the negative fuse.

The radio MFR put it there in accordance with the ARRL advice linked above.
Good to know.. I think short term, I am going to run like this and experiment a little.

Long term wise, a second auxiliary battery is the way to go.
 

PaulW

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leeshuming
Your install is just fine.
FYI, I follow the radio manufacturers instructions' regarding 2 fuses and I use the same pass thru as the coax to run the radio power wires directly to the battery. I use the ground on the lugs closest to the battery, battery negative would be even better. Does all this matter - probably not but my opinion is the less connections from the radio to the battery will be more reliable.
Your antenna location for a Jeep is confirmed as best by many experts.
My battery comments - turn the start stop feature (I use JL Tazer mini to do that but there are others).
12v AGM batteries that use pure lead instead of a percentage of recycled lead will last the longest. Lithium is on the horizon but cost hardly justifies replacing the Lead AGM. Last of all due to all the manufacturers software your battery will not ever reach a 100% state of charge. Compensate for this by using a maintainer as often as possible. Overnight is best. Figure out a way to make a maintainer plug-in simple. Find instructions on how to have the maintainer charge both 12v batteries at the same time.
 
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leeshuming

leeshuming

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leeshuming
Your install is just fine.
FYI, I follow the radio manufacturers instructions' regarding 2 fuses and I use the same pass thru as the coax to run the radio power wires directly to the battery. I use the ground on the lugs closest to the battery, battery negative would be even better. Does all this matter - probably not but my opinion is the less connections from the radio to the battery will be more reliable.
Your antenna location for a Jeep is confirmed as best by many experts.
My battery comments - turn the start stop feature (I use JL Tazer mini to do that but there are others).
12v AGM batteries that use pure lead instead of a percentage of recycled lead will last the longest. Lithium is on the horizon but cost hardly justifies replacing the Lead AGM. Last of all due to all the manufacturers software your battery will not ever reach a 100% state of charge. Compensate for this by using a maintainer as often as possible. Overnight is best. Figure out a way to make a maintainer plug-in simple. Find instructions on how to have the maintainer charge both 12v batteries at the same time.
I have a 4xe, I don't have the "start/stop" feature..

I do already have a battery maintainer that I use for my jeep as well as my wife's car. However, there is a very good 4xe owner who had done intensive testings and told me that a maintainer is not really necessary because the high voltage battery (hybrid) actually charges the 12v when it is being charged (would stop when the high V battery once it is full, or when it drops below very low).

I am most likely going to get an extra battery (isolated and purely for starting my jeep) under the hood and then an inverter which connects to my current AGM battery so that I can harness my HIgh Voltage battery and power my radio (and my fridge, lights, basically everything else) this way, 17kw should last me a long time. :)

Anyway, I might eventually need to move the radio and antenna to the rear of my jeep, I will see.

Again, this is a working progress..

Tks, now everything is installed, I am just waiting for the 10ft control head extension cable that I didn't know I needed.

I got this 1" ram ball, and a m5 x 35 screw bolt and some washers (I learned from another site).. see photos.. and is connected to the back of my radio.
See photos..

Let's see how this works.. I am a bit worried still because the face (head) of this radio is huge.

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Now here are my questions:

1) Which is a better location to ground my negative wire to the chassis? I see only 2 options: option a) to the bolt that is below the passenger seat near the center console? Or option b) to one of the 3 grounding bolts that is inside the panel of the passenger footwell near the door harness? Or it doesn't matter?

2) this is more important, do I really need to use the built-in 15amp fuse on the negative leads? Can I cut it? Or do I really need it? I mean in the event where the fuse of my negative lead pops, I would no longer have a ground and all the current would then hit and fry my radio?

Please advise,

Tks
1.) Not sure which ham unit you're running, but mine called for at least a 15 amp supply (Yaesu FTM300-DR) ... I went ahead and used a 40amp switch. I recommend referring to your particular radio's user manual.
b.) I routed my negative lead to the passenger footwell door harness location you mentioned.​

2.) I left all built-in wire fuses in place.

Further details of how I did my Ham install here and here. (Overhead mount above armrest)
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