View Full Version : Bonding....

02-28-2011, 10:06 AM
So this weekend I did some bonding.
First I bonded the tail pipe

02-28-2011, 10:08 AM
Hood bonding Passenger

and Drivers

02-28-2011, 10:11 AM
First is the antenna bracket
then the outside of the strap, then the inside. Basicall bonding the bracket to the jerrycan holder.

02-28-2011, 10:16 AM
I honestly can't tell a different after all this work. If you have comments, please let me know if I should invest more time into it.

This weekend contacts were from small town from west Sweden, Central France, Florida and one more place I forget.

The real thrill is contacting from my car, while driving, doing errands. I will take that over any stationary setup. One more thrilling reason to be in my Landcruiser.

I should be getting today the 40M and 10M hamstick.

I have problem getting the scan to stop. It scan right by conversation. My RF gain is back on 100%. My squelch is at the noise level. So most of the scan is quite. It breaks on S3 which is what I want. However the scan does not seems to stop even on S9 signal. Need to call Kenwood.

02-28-2011, 10:45 AM
You have the background noise squelched, which is similar to my Yeasus. So the way it works for me is that in FM or AM mode it stops and pauses. In SSB or CW, it just slows down.

That's because when the radio starts to cross an SSB signal that breaks open the squelch it may not be at the right carrier frequency, so it's giving you time to click the scan stop (PTT on my radio) and center the frequency (which is adjusting YOUR radio's BFO). Remember that FM and AM are set bandwidths with a transmitted carrier, whereas on SSB your radio is re-installing the carrier (remember SSBSC?) and so it has no idea when to stop. You do that with your ear.

FWIW, doing this automatically can be done, but it's a higher level of sophistication to the carrier recovery than is usual in ham radios and starts to become far more difficult when dealing with speech of so many different people, especially so when dealing with interference, static, etc. Turns out that what your ear and brain are awesome at doing (detecting minimum levels of comprehension) takes pretty dang powerful DSP. DSP works a lot better (e.g faster and needing less processing capability) on deterministic and periodic signals, neither of which the human voice really does.

You say after bonding you can't a tell a difference. When I bonded my exhaust in particular it made a huge difference in ignition noise. I still have a lot of alternator whine, but I haven't done much to alleviate it. It could be that your installation location is very good and so was immune to vehicle generated QRM inherently.

02-28-2011, 11:02 AM
I can control the speed of the scan. So I set it on slower.
yes, I can stop the scan with PTT and tune better with UP/DOWN on the microphone.
The scan start automatically after 5 seconds if I don't use the PTT or the UP/DOWN keys.

I can do all that while driving and not looking at the radio. The way it works now for me is that the scan find something and then I tune it better. Alas, then I have to look down and click off the scan. This is a problem. I can't stop and start the scan function from the microphone that came with the radio. Alas, money can solve a lot of things.

I ordered the Kenwood MC-47 microphone that has four programmable buttons. And you guessed it, one of the buttons can be programmed to start and stop the scan. So I should be able while driving and looking the road to: scan, tune, stop scan, and restart the scan and PTT. Amazing.

I don't have alternator whine. Thanks God.
I have pulsating noise that the NB is pretty much taking care of. However, I might install RF shields on the power cables to see if it can do anything.

I am not considering this project complete until I talk to you guys on the 20, 40 or 10.... while driving!!!!

02-28-2011, 11:07 AM
Your experience on tuning SSB is pretty much why I don't much bother finding all the sources of EMI in my truck. I am not talented enough to work the radio and drive. I'm barely competent at driving as it is... So I most do channelized modes and bands, sometimes I'll listen for 2m SSB activity, but that just means leaving the radio at 144.200. I do 2m because the antenna is on the roof and is MUCH quieter. :-)

02-28-2011, 12:14 PM
I meant I am driving while you on the stationary QTH.
Not going to happen with two mobile setups.

CO Hunter
02-28-2011, 06:25 PM
Just a thought based on your pictures. There is some rust and looks like powder coated or painted brackets. Are you sure you are getting good connections and they will stay good?

Funny, I was just up in Albany this past week. I flew in there anyway, meetings in Kingston.

02-28-2011, 10:01 PM
I would 2nd that idea of making sure you get metal contact. Just throwing a piece of bonding on painted parts will not effectively do anything, except maybe keep the bonded part from falling off the vehicle.

I had my 857 mounted near the center console. I could easily rest my arm on the top of the center console and tune around. It was comfortable. But I have had lots of experience listening with my father at home when I was younger. I have listened to poor radios with poor antennas and great radios with great antennas and also awesome radios with awesome antennas. I must say, with a beam antenna at 100' pointed anywhere with a well tuned radio and 1500W PEP AMP on your side, it is a nice warm feeling. You only get that with a less equipped station when you make that QSO that should not have been made. A 5-9+20 signal report from Spain at 4:30 in the afternoon traveling through Denver rush hour traffic gets me that warm feeling. Especially barefoot mobile.

Keep trying.

03-01-2011, 06:38 AM
You're such a geek Nathaniel. :-) I'm also horrible, I mean absolutely terrible, at copying call signs. I have to write them down as I hear them. I'm not sure what the problem is, but I'm pretty sure I'm getting dumber. Maybe there's something to this fluoride in our water thing afterall.

03-01-2011, 08:22 AM
Just a thought based on your pictures. There is some rust and looks like powder coated or painted brackets. Are you sure you are getting good connections and they will stay good?

Funny, I was just up in Albany this past week. I flew in there anyway, meetings in Kingston.

And you didn't stop to say Hi?

I cleaned rust, powedercoat and/or paint underneath the ring.
I used the serrated washer under to dig into the metal.

That said, on the hood, one connection is 1/4" washer which I had, the other is 3/8" which I did not have the serrated washer for it. I since picked some 3/8 and 5/16 washers and I plan to install these soon. I know the hood is really important to bond well.

03-01-2011, 08:23 AM
I would 2nd that idea of making sure you get metal contact...... Just throwing a piece of bonding on painted parts will not effectively do anything, except maybe keep the bonded part from falling off the vehicle.

Keep trying.

I am only sure about death and taxes.

03-01-2011, 09:27 AM
I know Dave will shoot me for this, but I also imagine that your particular antenna does not radiate efficiently enough to see huge gains from much of the mobile tricks to reduce noise and increase efficiency. I am not saying they can't make contacts, just that no one should expect it to perform awesomely, especially on the receive end.

The popular ones tend to be the Hamstick®, and the various copycats. All are very low in efficiency, as their Qs are about 50 or less. A few of the 80 meter models have Qs less than 10! If you want a really lossy antenna, use one of the stubby 3 foot long versions!

Their only attributes are, light weight, low wind loading (some models), and low cost (≈$20USD, less mount). This means they can be attached by just about any type of mount, some of which add to their overall losses (i.e.: license plate mount). Efficiencies range in the .3% to 20% (80 through 10 meters), and they typically don't need matching as the system losses bring the input impedance to near 50 ohms.

03-01-2011, 10:01 AM
Nah Nathaniel, I'm a nice fella. Really. ;-)

The Hamsticks are good for what they are, which are compromised mobile antennas. They are not really much worse than any other mobile antenna with the one main downside of having very small diameter coils. But even your Hi-Q antenna is a compromise and on the lower bands relies almost completely on the inductor radiating.

IMVHO the main downside to a Hamstick is they have very narrow bandwidth in general (this is a result of the coil form). They actually have a lot of radiating length, which is good. And they are electrically resonant, which is a good thing.

Don't fall into the assumption that low SWR or wide bandwidth makes an antenna any good at exciting electrons for a given frequency. It's about radiation resistance and uniform current distribution. There is no substitute for physical length and Hamsticks don't fall short there. Also the way they wind the antennas isn't too bad and this really distinguishes a decent antenna from a junk one.

I don't know what definition of radiation efficiency he's using (I assume it's KØBG), I'm not sure he is normalizing the measurement correctly to compare apples to apples. There's good reason why 'good' commercial engineering practice is a field of >120 tuned radials over a physical 1/4 wavelength radiator, this has been found to be what's necessary to guarantee a minimum efficiency over all conditions. Nothing about even a well bonded car is ideal and so they all rely heavily on the distributed stray capacitance to find a return. That's the real efficiency problem, the ground, not the radiating element so much.

03-01-2011, 10:13 AM
Dave, the fluoride's getting to you again! :D

I got my Hi-Q because I was convinced that their touting of a higher Q than other similar designs was attractive as a selling point. To each his own. I did, however, notice a dramatic improvement in my noise floor after doing the Same bonding as Rhyary. I did do my doors (all 4) and both upper and lower tailgate. I went from average S-6 noise floor to average S-3. Same location same time of day. No noticeable difference from day to day.

Some say my butternut vertical at ground level is a pile of junk, too, but with 4 radials I was able to hit Japan on 100W, and my house is in the way for that QSO. Make do with what you have, I say. I just didn't want Rhyary feeling the bonding he did was a waste of time.

03-01-2011, 10:44 AM
No man, I don't think the Hi-Q or Butternut are bad antennas, far from it. But in the Hi-Q example, it's not 20 times better than a Hamstick to justify their price solely on performance. Is it 2 or 5 or maybe 10 times better? Probably somewhere in there. But in electrons excited per dollar, the Hamsticks are clear winners over the expensive stuff. It's the law of diminishing returns. Your rig is about as good as it gets from a mobile standpoint.

Caveat emptor: My ATAS-120A was $250 and is mostly universally hailed as a pile of crap. I don't disagree. I know it'll never win me exotic mobile call signs. It does the job I ask of it and is much better than anything I could build similar to it. Works seamlessly with a minimum of hassle with my radio, for example. All I had to do is run a coax to get wall-to-wall 40m to 6m. In the tight confines of my truck that outweighed a lot of other variables.

You also know anecdotes are not proofs... :-) Someone else with the same conditions that you had to make a 100W contact might have done the same with 2W into a highly efficient dipole. Just hypothetical, but you get the line of reasoning.

I don't think bonding is a waste of time, it's something that you must do if you want any chance of mobile HF. BTW, I forgot to ask about the connection between the battery, 12VDC return, antenna and radio grounds. How are they done? I assume you ran the power supply return all the way to the battery, same routing and length as the 12VDC supply. Then the ground connection between the battery and frame (the frame is your common bonding point, right?). Just the stock battery negative to the engine block? If that's the case, you need to run a decent RF ground, a wire braid for example, to the frame from the battery negative.

Also the radio itself should be connected to the same common point as all the bonding. I ran a short braid from my radio ground lug to the cab floor (my radio body is mounted under the passenger seat). The cab itself is grounded to the frame and exhaust, so any secondary bonding I do, like the bumper, is done to the frame and does not need to run all the way back to the radio. Imagine the truck frame as your earth when comparing it to a stationary QTH. It's good enough electrically to consider it that way, as are large sheet metal panels. Never assume RF can make it past bolted connection, so if you are using a fender or door as a bond point, then that bond must be extended to the common 'earth'. RF can flow over a fender very well, but it will get stymied at the painted, bolted or isolated (like body mounts) connections and become a fantastic capacitor even if it looks like a DC connection.

03-01-2011, 11:40 AM
I don't want to make you feel bad, but my noise level is between S1 to S3.
Are you sure you have it mounted on/in a Landcruiser? :-)

(without the PRE amp. When I click in the pre amp (+12dB) the floor noise level go to 4 or 5.

I just got in a 1"x0.46" x 100 feet tinned copper strap. So I will be doing some more bonding to appease the RF Gods. :-)

03-01-2011, 11:44 AM
I don't want to make you feel bad, but my noise level is between S1 to S3.
Are you sure you have it mounted on/in a Landcruiser? :-)

(withought the PRE amp. When I click in the pre amp (+12dB) the floor noise level go to 4 or 5.
Is that with the engine running? If so, you're pretty much golden. I get that level of noise sitting still with the engine off from the atmosphere, power company and city even with the IPO on. I run with the pre-amp off on 40m and sometimes 20m, doesn't make enough difference in signals to make it worth it.

03-01-2011, 11:52 AM
Is that with the engine running?

Oh Gowad. You guys are relentless :-)

No, it was not with the engine running. Ran out side to the parking lot to test with engine running. No apparent difference with engine running or not. Same floor level. The only difference is that you hear the pulsing, but it does not change the floor noise.

03-01-2011, 11:58 AM
Oh Gowad. You guys are relentless :-)

No, it was not with the engine running. Ran out side to the parking lot to test with engine running. No apparent difference with engine running or not. Same floor level. The only difference is that you hear the pulsing, but it does not change the floor noise.
LOL! Relentless.

If all you get is S3 with the engine running, that is 4-to-5 S-units lower than me. My truck is an EMI nightmare, the alternator diodes are 21 years old, the ignition overtakes a 50,000 watt commercial clear channel AM station and the CD player turns out not to need an FM adapter... Hams a block away hate me, but I still like my rolling tetanus, radio-black-out experiment! :-)

03-01-2011, 12:24 PM
Dave, the fluoride's getting to you again!

Speaking of which...


03-01-2011, 03:32 PM
This question of efficiency has been bugging me all day. I think it bears some discussion, although I suspect I will be the only one interested.

I think one of the better (sorta) lay descriptions for efficiency comes from Tom, W8JI


He says, in part,
Folded monopoles provide the clearest common example of radiation resistance misuse. Quite often, in discussions of vertical antenna ground system loss, claims are made that multiple drop wires increase radiation resistance and lower earth or ground system losses. The justification is multiple drop wires, or a folded monopole element, increases radiation resistance. The increased radiation resistance reduces ground currents and ground losses. This concept is justified and/or rationalized through use of the common formula eff % = 100 * Rrad/(Rrad + Rloss) .

Losses must be normalized to the same point where radiation resistance is taken, otherwise the efficiency formula above does not work! Many folded monopole articles either ignore the fact that loss resistances must be normalized to the feedpoint, or the authors are unaware of that rule.

So total efficiency is given by several factors for physically and electrically short antennas, which if you notice means that most of our space limited antennas will have very low radiation resistance but high radiation capacitance, necessitating lots of correcting inductance to minimize antenna reactance.

The definition (non-normalized) for radiation efficiency is given by:

Radiation resistance Rτ
Ground-terminal resistance Rg
Resistance of tuning inductance Rc
Resistance equivalent of insulation loss Ri
Resistance equivalent of conductor loss Rw

Notice that ground resistance, tuning inductance and losses all reduce efficiency and so even a physically good antenna is ultimately subject to the same factors as a poor one, which is why when you read eHam you get so many 1-of-5 AND 5-of-5 for the same antenna. Also notice that radiation resistance is both in the numerator and denominator. If you take the time to do good return work, a Hamstick has sufficiently high radiation resistance that it can match fairly closely the performance to higher dollar units. IOW, it's often the care and feeding of the antenna and feed that makes or breaks it and even a random length of wire can work pretty well with the right conditions.

Ultimately, the measure of efficiency, though, is how much power is contained in the generated field vs. input to the antenna. This is where most theoretical efficiency descriptions get sidetracked, because they assume feedpoint characteristics that aren't necessarily true. Anyway, the sure way to include all this theory is to measure power into the antenna and field strength some distance afield. When you do this you defacto normalize and can compare. To which the real world experience of rhyary starts to make sense, what he's doing is simply working pretty well!

03-01-2011, 10:14 PM
This question of efficiency has been bugging me all day.. although I suspect I will be the only one interested.

:bowdown::lmao: :lmao::lmao:


03-02-2011, 10:27 AM
So last night I mounted the 40M hamstick.
I am now getting in to Groucho territory. My noise level sits at S5 now.

The SWR is 1.5 around 7.200 and gets up to 2 around the 7.150. It also get up to 2 when I get up to 7.3. I have work with antenna tuner to see if I can get it better by just adjusting the whip length.

So if I am getting S5 on the 40M, would that be the equivalent of S3 on the 20M?

Does the 40M shows me better the need to do more bonding?

I got the 40M to try night time RF, but I was able to QSO with Wisconsin and Maryland this morning on the way to work.
Wisconsin gave me 5-9+20 and Maryland was 5-7.

Noise is significantly more present than the 20M.

Dave, I do plan to read your efficiency post, primarily to understand the kind of things that bug you :-)

03-03-2011, 01:18 PM
Was able to QSO with operator 40 miles north of Denver using my mobile 40M hamstick. His signal was 4 7. Mine was reported 5 - 9.
Just saying :-)

04-26-2011, 10:18 AM
My truck is an EMI nightmare
Made a significant change last night. I installed my common mode choke that uses 50 ferrite beads on a length of RG-58. They are mix #31 and it replaced the toroid I had the HF feedline wrapped around. This morning I gave 40m a shot and nary a tick to be heard, just that blessed sound of the cosmos. Yippee! I'm wondering now if the ferrite I had was maybe not the mix I thought it was now. On 6m the ignition noise is evident but doesn't move the S-meter, which is exactly what I would expect with ferrite #31, that it would be much less effective at 50MHz than 7Mhz.

BTW, heard a Japan station on 40m at 7:15 local. He was obviously having QSO with someone I could not hear, so I didn't burst in. He was only S5-ish, something that was normally swamped.

04-26-2011, 11:21 AM
Where did you get the ferrite beads? I currently use a toroid like system, but I would love to just hear the cosmos.

04-26-2011, 11:28 AM
I usually get ferrites and iron cores from CWS Bytemark. Newark carries some interesting ones, although they are not my first go-to. I have also gotten a few from Amidon.

I don't think the key was beads-on-coax, but more the material and the amount of material. There is about a foot and half of beads on the choke right at the radio connector, it's really sorta awkward since my radio is under the passenger seat and the coax is poking out like a tentacle. :-)

I do plan on re-turning the choke using known material toroids or maybe binocular cores and putting one on each connector (probably mix 67 for the VHF) and one at each end of the HF feedline. Putting the choke in or wrapping it with something to protect it from getting broken.


Common coax cable type outer diameters.
RG-58 is 0.195"
RG-8X is 0.242"
RG-8 is 0.405"

04-26-2011, 01:31 PM
BTW, if anyone is thinking about an order LMK and we can save some shipping. I need a few parts, but it's no hurry.