Mobile Antenna

[tweiss3]

I'm a bit new to radio. I drive a lot, traveling with my company car. I've been using a CB with a magnetic LilWilly whip antenna. I also have to have access to the weather (outside of my phone) and always thought radio was cool, so I have a BF-F8HP that I have been using for analog scanning, which is a benefit because I get the county skywarn channels for weather alerts as well.

 

Anyways, I decided to grab a GMRS-V1 to be legal since I filed for my GMRS license. I have noticed, half the time if there is GMRS chatter, it is only picked up on the F8HP and not the GMSR-V1. Since I'm in a company vehicle, drilling is not an option. Should I go with a magnetic mounted antenna or just get a better 8" whip that is 1/4 wave. If i went magnetic, i'd get a triband that would have me ready for either a true 50W mobile rig or digital mobile scanner (P25 capable). If it helps, I currently clip the radio to my sun visor while scanning.

 

If magnetic, will there be a grounding plane required (similar to CB)? How large? Will it interfere with the CB?

 

If upgraded whip, any affordable optiosn other than Nagoya NA701C? 

 

I'm currently studying for my amateur technician test, but I still have so much theory I don't understand yet as far as antennas.

 

Thanks,

 

[wayoverthere]

I've been researching DMR radios as well, and one thing I noticed is that a number of them are part 90 certified, which few of the consumer ham radios seem to be

[Lscott]

Now I just have to find time to study for my technician exam, because I definitely want to get that taken and put behind me soon. I don't do well with tests.

I'm not sure about the exact model radio you installed. Many of the Kenwood's will program down into the Ham Band even if the software pops up a warning about the frequency being out of range. Most of the simplex and repeater operations on the 70cm Ham band are between 440 MHz and 450 MHz. I have a collection of HT's, 4 watt radios TK-370G-1's, that work down to a bit above 440 MHz I use for both Ham and GMRS.

 

With a 1/4 wave antenna the bandwidth can be rather large. I built a small one out of some stiff bus wire and a BNC connector. The SWR was below 2:1 from 430 MHz to 470 MHz covering the usable section of the Ham 70cm band and all of the GMRS frequencies. If you can do that with the antenna you installed, and the radio will program down low enough, you can have access to both services on UHF with just one antenna and radio. Most radios work fine as long as the SWR is 2:1 or less. Not a bad deal if it tunes right.

 

You can do a frequency sweep and see where you're at. If the low SWR point is a bit too high you can get a replacement whip and cut it a bit longer to try to cover the GMRS frequencies and as much of the Ham 70cm band as practical.

 

Good luck on trying to get your Ham Tech Class license. The test is pretty easy. I went to a Ham swap once many years ago with my brother, who was already a Ham, just to look at some test gear, and he offered to pay the fee if I sat for the Tech Class test. I had no idea he was going to ask me try try it. I said OK it's your money. Surprised, I passed with no studying! 

[tweiss3]

Yea, I can program from 327 MHz to 550 MHz in KPG-79D (with it yelling at me out of range). Any further outside of that it doesn't keep the frequency. Many agencies around here are still on UHF and have not made the jump to 800, though Ohio MARCS is getting them one by one.

 

I programmed it in a way that makes sense to me:

Zone 1 - GMRS: CH1-7, CH15-22, RPT15-22 CSQ, Known Repeaters

Zone 2 - County 1: Local Hospitals, County Jail, Malls, School Districts, County Highway Engineer

Zone 3 - County 2: Local Hospitals, County Fire, Twp Fire, City Fire, City PD, Twp PD, School Districts

Zone 4 - County 3: County Engineer, RTA, Local Schools, Local Traffic Reports, News Station Ops

Zone 5 - GMRS Travel: RPT15-22 141.3PL wideband, RPT15-22 141.3PL narrowband

 

Everything non GMRS has no TX frequency even programmed. Got to keep the wife out of trouble. Ends up just shy of completely full. I still have been using the BF-F8HP for VHF scanning (quite a bit of that around here too).

 

I did set myself a hard deadline. I found a local Laural sponsored test session (free) on July 9th, so I'm taking it.

 

As for digital/DMR, the AT-D578UVPRO is part 90 certified. It's brother, the AT-D578UVIIIPRO is Part 15 certified and has 220 capabilities in it. From what I have read, the hardware is identical just a different sticker and firmware. Any say on 220? Would it be used often?

[Lscott]

As for digital/DMR, the AT-D578UVPRO is part 90 certified. It's brother, the AT-D578UVIIIPRO is Part 15 certified and has 220 capabilities in it. From what I have read, the hardware is identical just a different sticker and firmware. Any say on 220? Would it be used often?

I have the D878UV HT. The radio itself seems to be mostly OK and not a bad value for an analog - DMR HT. The main issue I have is with the darn programming software. One version they fix a number of outright bugs. It's good for a version or so then they bugger it up again. It's really frustrating. It's like there is no quality control and no version control. You would figure once they fix a bug it would stay that way, nope. I reamed their tech support out over this issue several times by email. Of course it's all in China so how much do you think they are going to care.

 

I haven't even bothered to load the latest firmware release. I did try the radio programming software. Some stuff they fixed the other things that I noticed they didn't bother with fixing. 8-/

 

Normally when they do an update they issue both a new firmware file for the radio and a new version of the programming software. They likely need to do this because the memory layout changes from one version to the next for the code plug. The notes say to save the code plug using the old version then reload it using the new one. The last update was so bad they had to issue an update just for the radio programming software. Right now the radio sits around and I'm not actively using it. I'm waiting to see if they finally get their act together. I'm just about done with the bugfest.

 

Now about the 220 band. The activity seems to be hit or miss depending on the area. Where I'm at, Detroit metro location, I haven't noticed much use. Other places I hear it's popular. If you can get a radio that includes it without a significant cost premium I would say go for it. The reason why it's not more common is the band is not a world wide armature allocation like 2 meters or 70cm bands. Most manufactures don't want to include it because it is pretty specific to ITU region 2 which is where the US is located. That leaves out about 2/3'rd of the world wide market.

 

One other thing. You can find amplifiers easy enough for 2 meters and 70cm. Good 220 amps are hard to find. I've looked for used ones at Hamfests and haven't had much luck. The ones I have seen are beat to crap and or the seller thinks it made of gold with a price to match. The only cheap FM one I have seen is from Btech. I've read some mixed reviews on them. Basically it's just to boost the power from an HT. I've thought about getting one for my Kenwood tri-bander, TH-D74A, the price is cheap enough considering.

 

https://baofengtech.com/amp-v25

 

Dual band antennas for 2 meters and 70cm are also easy to find. The two bands are harmonically related, 70cm frequencies are approximately 3 times 2 meter frequencies. That makes designing dual band antennas reasonably easy to do. However 220 is not. So finding a tri-band antenna for 2 meters - 220 and 70cm are not that common. One example is the SBB-224/SBB-224NMO.

 

http://www.cometantenna.com/amateur-radio/mobile-antennas/ma-tri-band/

 

Most likely you will get a good dual band 2 meter and 70cm antenna and a separate one for 220. Then you use triplexers and patch cables to split out the 220, or just use a coax switch to flip between the antennas.

 

https://mfjenterprises.com/products/mfj-4936s?_pos=2&_sid=060a07025&_ss=r

[n4gix]

For Analog/DMR I really like the Connect Systems CS800D (dual band V/U) which also offers a detachable faceplate. It is also Part 90 and 95 certified. I have mine programmed for both amateur 2m/70cm use as well as GMRS.

[tweiss3]

That's a nice option. I keep seeing those pop up when looking at other people's mobile shacks.

[tweiss3]

Finally mounted the head permanently. 

Final Head Location by tweiss3, on Flickr

Drivers View by tweiss3, on Flickr