I lost the plot with this mobile ham radio setup
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- Опубликовано: 9 апр 2023
- I have to be honest and say I can find better ways to pass a few hours than to try and get a Land Rover to perform well on HF radio. I've got issues with RF affecting the old Icom 706 mk1 radio (which is also a poorly radio).
I am getting RF into the vehicle which is affecting the performance of the Icom and affecting the transmission. It may also be affecting the ability to tune in the Tarheel antenna on 20m.
I really need to bond the vehicle to get a good ground without making the car look like Dougal from the magic roundabout with the radials draped over it. I also should wire the radio into the vehicle properly with ground to stand a chance.
I'm also thinking the 2/70 antenna on the roof may also be bringing in RF on it's outer shield.
I'm a licensed amateur radio operator from the United Kingdom. My RUclips channel features videos focusing on operating portable radio from various locations plus how to videos, tutorials, insights and conversations in the hobby.
Opening line with the beeped out F bomb had me creased! Always enjoy your content Carl. Good luck!
When I used to work out of the car, I set up a tripod with a 17.5' MFJ telescopic and half a dozen radials. Worked well. And less painful than turning the car into a cat's cradle.
Carl, I really like that you did some on the job soldering, you always have the tools to fix anything that needs to fixed or to try out a new antenna or what ever comes your way to make it work, great job it certainly gave me alot more insentive, can't wait until your next video!
Hi Carl, congratulations for your entertaining and informative videos. Tests I made have demonstrated that the best place for an HF antenna on a vehicle is on a 5mm aluminium plate bolted under the front bumper. Not sure, but ground proximity and a slightly longer distance between radio and TRX could make the difference. The intensity of the near HF field is often underestimated. Even better results have been obtained as you suggested with a tripod at about 10m of the vehicle. Chameleon or equivalent, EFHW's on fishing poles or an inverted V will work nicely. Can be fixed on a spike or against a fence near your parking space. All this is OK if you are operating /P from your LR. While driving I mostly use VHF / UHF so no problems with mag mounts or window antennas. Hope this helps!
73 de Alex, HB9CKR
Nice work Carl. Hope family life is heading a better direction. At least you was messing about keeps the mind busy. It's like me that everything I want to do radio there is always something that gets in the way.
Good efforts
Motters M7TRS 73
Take courage Carl. It wasn't a waste of time. You've learned what doesn't work. Every failure illuminates an alternate path that might lead to success.
Remember Carl, it's good to make mistakes even if only to learn why you shouldnt make them!
I would connect those aligator clips to the bolt in stead. they are insulated from the ground plate by the paint/coating.
Ham radio can be used mobile in the UK, perfectly legal.
When I had my 706 in my discovery it would feedback through the rear speakers and would cut out if the power to it was a little restricted. I ended up using a 105ah auxiliary battery and the MFJ voltage booster. That cured the drop out, I cured the feedback in the rear speakers by throwing them away, the front ones got simple clip on ferrites.
Love the honesty Carl 🤣🤣hope you'll be back soon 73
ITS THE GROUND! JUST LIKE THE ATAS FROM YAESU. THE INSTRUCTIONS EXPLICITLY SAY DO NOT USE A MAG MOUNT. YOU MUST USE A LIP MOUNT ON THE DOOR AND MAKE SURE THE DOOR IS GROUNDED TO THE BODY. TRUST ME CARL
Just recently tried mounting a whip on a mag mount on the roof. Luckily no wind. 17 feet of whip on a single mag mount. Like you said and often do, a tripod is the better and safer bet. Or a spike. Chameleon's ground spike and micro unit and whip work well, too.
We all have crappy days Carl, you'll get it sorted soon enough. Good to see you being a little cheeky though! LOL! It's all good my friend!
🤓
Callum is such a Chad.
You need to match the impedance at the feedpoint, if you can't do this with some sort of matching technique such as capacitor (if it needs more), or stub matching etc. then you should try to add or subtract lengths of coax. This will at least match what the radio sees. The RF issues should go away. Try to borrow an analyser and see what the impedence is at the feedpoint, try to avoid odd quarter wavelengths (or harmonics of that) of feedline. Another thing you can try with that magmount is to put some thin rubber material between the car and the mount, you could also try other materials. The easiest fast fix is coax length, assuming everything else is in good order. I'm trying to see where you attached the radials. Try attaching them to the vehicle rather than to the mag-mount. Mag-mounts and stainless steel whips work in mysterious ways!
Back in CB days i fitted a welded up heavy duty bracket to a roof rack which was grounded to the vehicle in the 4 clamping points for the roof rack. There was a heavy duty aluminium pole that could come up and be held in position with a locking pin. we put an Avanti SIgma IV on that and it worked amazingly well, later we brought a pump up mast with us which worked even better. The steel plate was around 8mm thick and at the front i had a bolt through mobile mount for firesticks or a 102" whip. Solid! But, yea, the way mag mounts match the impedance is pretty fussy. try coax lengths first and go from there, get a female to female SO-239 and some random lengths of coax to put inline. Try 1M extra first. If this solves it then later you can also try shortening your coax. Try different bands to see if the RF persists all across the bands.
If when you tune your antenna to it's band (if mono) your SWR is not coming lower than 1.3 or 1.4 you might want to check the impedance. Tuning it out with coax lengths is not ideal but stub matching with a Tee connector could also work quite well. Check you do not have any power cables wound up in a loop!
In any-case i would scrap the magmount and work out some sort of solid bolt through bracket with good grounding to the vehicle.
I remember I used to bring my tri-magmount out to the park with a simple hamstick and stick it on an unused BBQ grill and get fairly decent results running QRP. One time the ground connection broke and separated so I had to settle for running cheap telephone wire from my bag as a long wire and that day was an absolute FLOP! I went back home and drank two ice cold beers and everything was okay again. Magic!
We are doing experimental radio. This experiment went wrong, like many experiments of mine. 73 and better luck next time…
Nice video as always - whatever the results ! Keele is such a nice campus , I train at the conference centre several times a year, latest is July 2023. Mark, 2E0MSR
Over the years I have found the most common RF mobile problem is RF pickup on the DC feed. I always add a ferrite choke close to the DC input. 73 Peter.
Congrats Mr Carl on reaching11k subs. Well deserved. Im a great believer in experimentation beyond the "Theory" side of things. Give it a go. Click and Collect some QSO's. It either works or it dont. Thats "Leicester Speak" for "It Does Not" 🙂
Get a ferrite donut and wrap a piece of coax around it. That should stop the common mode current from flowing back to your transceiver, which frequently happens with mobile setups.
Hi, great video, I use a td5 to get out and about, when working out of the car I use a simple ground spiked slidewinder coil and either a 2.4m or 5m whip antenna with a few feet of feeder and if necessary a radial or 4 (depending on ground conditions). I also used a diamond bb7v endfed and was really happy with it, though it's normally attached to the qth. It's interesting that I also had issues with ham sticks on my LRs roof, though could have been the roof rack. Great video, thanks.
2E0OWI
I’ve had the same with the Atas for all the same reasons.
Hi Carl, I sent you an email. You seems to be having a bad outings or two. I loved the starting line BTW.
Agree, we have all had these experiences, and if not you aren't trying hard enough. For a quick deploy on the Land Rover, try to fashion a mount that can be bolted to the spare tire (carrier) then 12 radials in a semi circle behind the Rover. Also, I think the RF choke should closer to the radio. This allows the shield of the coax to operate as a radial, yet chokes the rf in the shield before the radio. I use a homebrew feedline choke with 5 snap on chokes at the radio connection.
Ahh one of those days, we all have them. At least it was dry. 😊 Keep at it you’ll get there. I have a panoramic roof on my car and I thought it was going to be a nightmare and whilst it’s never going to set the world on fire with some ham sticks it works ok.
Hi mate - my 706 does that if the Voltage drops - they are well known for it. Also check the fuses if any in the power cord.
try the Diamond MAT-50 Ground plane for magnetic mount & HF antenna worked for me and my ATAS 120A
The metal body parts of the vehicle might likely are becoming parasitic elements with this set-up. Bonding the various pieces of the vehicle to ground would likely clean up the stray RF, as you say. Though ground strapping all the various panels and pieces together is a time consuming task. Thanks for sharing your time on this set-up, it's instructive.
hi carl, love this type of realistic video. Obviously iam no one to listen too, radials draped over the vehicle may be trying to make the ant a ground plain with above ground radials, but normally i think there would be tuned radials of say 2 or 3 required, so a bit of a conflict going on there maybe. also, was that car park covered in metal work of some description ? as you say, the same ant set on a tripod with radials away from the car, or even using the metal covering thats already on the ground might work. A simple vertical with a number of verticals , in my experience always works well. I know tim g5tm works from a car, but do you know if rf could effect any of the electronics within a modern car ? keep up the good work carl, look for your next one. 73.
Hi Carl, looked like your radials were connected to the mag mount via croc clips. If so, is it touching bare metal, or is the mag mount painted? Can't tell from the angle.
:Draw me a Dinosaurs Head" 🤣 I can just hear Callums Sid James's Laugh 😂.
Drive on Mast stick a DXC up, Job Done 👍,Another great Vid Carl
Hey that carpark looks like it has some kind of metal grates or grill in the ground. When I was watching your video I was thinking if that is metal that is an already made massive ground plane. Could you use an antenna and test to see if that carpark metal works as a ground plane ?
I don’t run any amateur radio gear in my Land Rover as it’s a RF maker!!!
Your ok if your parked up engine off and running an external antenna but it’s a waste of time trying to use a mobile antenna in my experience.
Good luck sorting it.
The RF may actually be controlled if you use a 1:1 choke balun at one or either end of the coax ? I had the same problem in my shack set up and it worked well (untill all the house around suddenly got solar panels "!). I also suggest a grounding spike driven into the earth about a foot (more is difficult to extract. ). 73 M7BLC
Hello, Instead of radials, try attaching the base of the antenna to the tow hook with a ground strap 10/25 Sq mm copper tinned, per m.
Give it a try / 73
Oh that’s interesting! Thanks
@@M0SZT I've been able to tune some antennas with this solution, then tell me if it worked / 73
There will be all hell to pay if you burn those exquisite tops on your units in the Disco.
( Lesson personally learned by soldering on the kitchen worktop - XYL suitably impressed. NOT !!! )
Good decision - dead horse well and truly flogged Carl.
Cheers, I’ve got a wooden unit that I’ve added on top of the drawer in the Land Rover, it’s plywood and is the base for my bed.
Our of interest Carl what was the voltage on the706? Sounds like Rf issues when a 706 has low voltage, but as others suggest it is likely a grounding issue.
That’s interesting, I could do with measuring the output of the battery
Are you still powering from the portable power pack.?
Get rid of the power pack and connect the radio to the vehicle battery.
Connect radio ground to car.
Hi Carl
Is the Landrover connected to ground, I remember years ago having an earthing strap going from an exhaust bracket at the rear of the car with a strap/chain touching the ground to prevent static. Would a similar approach help with the RF? I'm an M7 and still learning so apologies if this is poo!
It’s a good idea grounding the antenna, even driving a steak into the ground would help to get stray rf away from the vehicle
Hi i always found mag mounts to be poor bellow 21mhz its the capacity between the magnet and the car you can not beat agood anttena mount fitted to the car and a good earth connection to the chassis i used to run 400w from my car never had rf trouble anyway i am shore you will sort it chris chris G0WFH
Yes, you have lost the plot LOL. I also have a Little Tarheel, and have used it on a number of vehicles - currently on a Land Rover Discovery 3. Never an issue with RFI or tuning. Why all the radials ? That was funny - walking through a curtain of radials getting in and out the SUV. Fit a proper lip mount that makes direct contact with the metal of the SUV - not magnetic mount, and Bobs your uncle.
Did you say...
you're not allowed to talk on the radio while driving?
You’re not allowed to use a microphone or operate a radio, well in fact you can but with the recent changes to the law you are much more likely to be pulled over
Is that a steel grate you are parked on?
It looks like some sort of wire mesh alright.
Hi, more likely a plastic former that is infilled with soil for a hard(ish) standing and the grass grows up through the grill. Hope that makes sense.
@@MI7DJT Won't that interfere with your radials?
@@M7TFT Makes sense!
I'm assuming it is just plastic, but it may contain wire??
Weird as sh*t mate!
Your problem is 2 words.
LAND ROVER
Actually, yes you are allowed to use your radio whilst you are driving. So long as it does not interfere with your ability to drive it is perfectly legal.
It even states this in the foundation license training manual.
The driving whilst using law is dictated by the frequency of the equipment you are using.
So nothing in the microwave bands and phone bands is permitted but anything from 446MHz down to 1.8MHz is perfectly fine.
Take note that using "network radios" is not legal as they are connected via the mobile phone network and therefore technically your are using your mobile whilst driving which as you know is an offence.
Guess you didn't want my advice. My comment has disappeared.
When was the comment made, I’ve been watching telly for the last couple of hours 🫣
@@M0SZT It was just before I posted this comment. I had offered some input based on my experience with HF mobile and referenced a video I made about it and how I bonded my magnetic antenna base to the vehicle. Maybe it was put on hold for review due to the video link.
land rovers are not the best vehicles i found only really good for vhf/uhf due to rf and they are rubbish for earthing. some have airbag supension and all seem to have floading earths these are rubbish. i had a land rover discovery and had same issues you got. chnged to a mitsubishi shogun same radio same antenna worked brilliant. so mobile in a land rover forget it its not your set up but more likely the land rover discovery. i feel for you i really do it frustrating
I reckon you are better off sitting at a camp table rather than in the vehicle… looks really uncomfortable sitting in the backseat playing radio!!!
Hi Carl, I use a Scorpion screwdriver on my Suzuki Grand Vitara and I struggled for about 8 months to get it to tune from 160mtrs to 10mtrs on full power. Unless you have a reasonable mount which is grounded to your vehicle and carry out some vehicle bonding (doors, bonnet, exhaust etc) then your will probably pull out even more of your hair than you have done already. Keep at it mate, you'll get there. Regards, Carlo. G7iru. Email me if you need any pointers via qrz.