Amateur (Ham) Radio BS and Callsign Thread!

Also anyone using the rt systems software is it worth it ?

 

“Antenna Gain Patterns” attempt to predict what direction in space (3D) a particular configuration will produce. They are not absolute, as they are data points measuring some gain at certain frequencies. For your goals these are “examples”, with the takeaway being it is typical to see a trend of a more symmetrical pattern when the reflective plane is also more symmetrical. Or, center of roof is more even than on the bumper.

Just because it can be measured, doesn’t mean it is true, or that it matters. And small moves towards center of mass can help if you have drop outs or truly one direction bias. Most old timers have their transmitting antennas high and centered, because it both theoretically and for the most part in the field works well. Some CB drivers (long haul) will keep it off to one side as it may give them more distance along the path of travel.

The phrases “ground plane” and “ground” are often confusing and hotly debated (in a jovial and fun way as is the norm of hams, not like the debates over oil change intervals)...I digress, for the gain patterns (remember that was the question I’m answering!), consider your whole truck the “ground plane”, not just a space like the roof. Think “center of mass”, then tighten you radius from you antenna to 3x your wave length, and 2x and 1x etc...the further away inside these concentric circles you have stationary interference (vertical metal shit), the less likely it will couple (fuck up) your transmit signals...so for 462Mhz, try not to have vertical metal surfaces within two feet for 1x.

GMRS 462+ Mhz FM benefits from a vertical antenna as high as possible (FM) that is tuned to typically a 1/4 wave. (About a smidge over 6 inches), so they are popular with recreational/family usage.
These are line of sight transceivers, so yes trying not to block the antenna on the horizontal is good practice.

Hopefully others will comment, as these are really my opinions.

 

Thank you!

These posts really are helpful. I never would have expected that a 6” antenna in the middle of the truck would be better than a 32” mounted on the rear. It’s just so counterintuitive; I expected the longer antenna to be much better, particularly based on Midland’s marketing: “This 32-inch whip antenna quadruples signal output... maximum range... 6db gain.”

 

Well they aren't wrong...just that you need to mount it in an optimal spot to get those figures.

 

Also, my main concern is receiving signal.

I don’t seem to have any issue transmitting.

 

The above is the correct theory, its just that
The below makes more of difference
Do both!

 

One more thought - the vehicle can block some of the effective antenna length.

Think about a bumper mounted antenna - the length of antenna from the base to the top of the vehicle is essentially not effective, due to (I believe) the absorption of the signal by the body of the vehicle.

A shorter antenna on the roof will be (potentially) more effective than a longer one on the bumper. Yes, there is a lot of theory/physics I am glossing over.

For simplicity, I have always mounted antennas on the roof - high and centered in the vehicle.

 

@Red Baron

 

When you realize how much RF is capacitive, then it starts to click.

 

Got my call sign today. KJ7LVZ. No one to talk to And my TNC and radio aren't clicking yet. Tomorrow is play day, now I can figure things out.

 

Just made my first call. Hit a repeater about 35 miles from my location and got a confirmation from a guy about 75 miles from my location.

 

That’s always a good feeling.
Congrats!

 

I'm just over in GJ, let me know if I can help.

 

I cannot say enough good things about that rt systems software. It took about 20 minutes to get everything loaded into it and set up the way I wanted it then about 5 minutes to go out to the truck with my tablet and program the radio.

 

Is anyone going to mobile mount the new Icom IC-705.

https://www.icomamerica.com/en/downloads/DownloadDocument.aspx?Document=1031

 

We’re going to be here all night for Winter Field Day. Working some sat’s in about an hour.

 

I have the same travel trailer! We are currently putting ours up for sale.

 

So on the drive to work I was scanning through my saved frequencies. Somehow I accidentally programmed several gmrs frequencies in. From my understanding I can listen and still be perfectly legal right? I just can’t transmit.

 

You are only allowed to transmit in the frequencies for your license. The ARRL has a handy bend chart that lists the frequencies for each ham license level.

 

Correct I know that. I’m asking if i need to remove that from my programming or am I good to just listen on it.