Amateur (Ham) Radio BS and Callsign Thread!

Ah my bad. Guess they're still good for a few more months at least. Still, should be enough time to get a license if you can fit it into your schedule.

 

The estimated loss is about -2.4dB vs center of roof.

 

I have a question about grounding my Diamond 770. I've read that it doesn't need a ground to work, but would providing a ground by running a grounding cable to the frame provide a better SWR or would it have no effect?

Edit: The mount they gave me for the antenna is for clamping it to a mirror or a rack, not to a bedrail. I can probably use this anyway since I still have those stock bed tie-downs on the rails and there's also those D-ring like attachment points near the front of the bed. Any of those places sound either remotely viable or should I just go and swap out the mount?

 

Added an external speaker for my ham radio, since the built-in speaker just wasn't cutting it. Was a fun little "fab" project - I find woodworking so much easier than metal...

full story, more pics: External Speaker for Ham Radio

​

 

Nice clean work. Love the finger joints.

 

Got my tech a few months back and I was using hamtestonline.com I believe. I used one of the ARRL books as well but had a hard time retaining knowledge. Essentially all the testing does is force you to memorize answers which doesn’t really teach you a lot but it helps get your feet wet. Would be a good place to start.

 

The first two test Technician and general. Are that way. The Extra class is not so. Alot of the answers for the questions are the same but one word. So you have to know proper answer

 

@thefatkid

 

So where I'm thinking of putting mine shouldn't be an issue. I'll be on the front for the roof about 1' back from the windshield, we will see. I'll drop the tent on there 1st to see, might just mag mount it for now then figure out if I'm going to punch holes later or mount it to the rack.

@DaveInDenver have you seen or heard of any issues with rack mounting. Rack shouldn't be ground isolated from the vehicle, will be aluminum though. Was thinking of 2m/70cm off of drivers front and HF passenger front, so they are about 4' apart.

 

What are your plans for HF in the truck? I am honestly curious because my limited understanding of HF is it is used for long distance contacts from 100s to 1,000s of miles away. I always thought that a lot of HF communication was basically just making contact with people from far away places to "check them off the list" and exchanging call signs and locations. Educate me!

 

Guessing he's referring to CB

 

Maybe, but maybe not. I know there are a lot of hams out there who run HF mobile units, but I havent had the chance to ask one what they do with it.

 

Mounting on a roof rack can work fine. You already know that the rack must be electrically connected to the vehicle.

Should mention that this means both to DC and RF, which aren't always the same. You might get a decent 12V ground but have a terrible RF path, so even if a DMM shows continuity you need to be ready to address a poor SWR reading. Electrons excited by RF are a lot more particular than their neanderthal DC brethren. RF is the 200 series driver of the electromagnetic fields world.

The fix could mean several things but usually it's that you need to clean off paint, rust, maybe galling on stainless or a zinc wash on fasteners, etc. A general method to solving mounts on racks, bumpers or swing-outs is braided ground strap between large chunk of steel. IOW, the rack itself to the roof or a swing-out to frame.

Another thing to watch with roof racks is getting a sufficient counterpoise (ground plane) under the antenna. Sheet metal is ideal for this but mesh floors might or might not work. This depends on the spacing of the mesh and the frequency (wavelength) you're using. A wide weave will likely mess up UHF, for example. It looks like a lot of little passive elements rather than act like a plane.

 

I used to have mobile HF but it's not really worth it for me. It's not easy to operate mobile and trying to deal with tuning the antenna and tuning stations. Meh, I just take HF portable and set up on a table in camp, barley pop in hand, a pair of headphones on perhaps.

 

So might be best to plan on punching a hole in the roof. I'll have to see how it works once I get the truck back. I was thinking the RF would just couple in a similar fashion to a mag mount directly on the roof.

 

I've always liked AM and SSB, long distance contacts are fun. With CB it was cool if you stayed away from the power channels, Hoping with running licensed frequencies it will be easier and more respectful. Kinda hope to set up a dipole antenna at camp some day, out in the country where there is less ambient noise.

 

That's exactly the analogy, a mag mount. The reason a mag mount is worse than a drilled hole is the small gap between the roof and mount creates a capacitor, which creates an impedance to current flow.

 

BTW, with VHF and UHF it's always best to drill a hole for an NMO mount in the middle of an expanse of sheet metal. But this only means your antenna will work well, you still have to make sure to deal with conductive things around it, such as roof racks. They will become part of the antenna so you need to make sure they are grounded and/or tuned. If there's going to be a rack near your intended antenna location you could actually be better off with it on top of it.

 

KM6PIM here. Just recently got my first technician license.

I'll likely go for general soon in an effort to establish contact with my dad's station in New Mexico