Discussion in 'Mobile Radio Systems' started by K4VUQ, Mar 1, 2016.
Here is the MasterMobile ad. The image isn't that good, but maybe it will help.
Man you assume to know so much that isn't so about me. But its okay. Moving along, nothing to see here boys.
So you say i'm close minded and blah blah but you praise Alan when he said the same thing just before me, haha. Classic selective attention.
When I am considering mobile radio application, I tend to consider what the Army does. You can't get a more serious use case than that - in time of war, if the radio fails it can be disastrous, and sound quality needs to be high in order to again avoid problems. And the Army uses whips and tuners for HF. Why? First, it gives the widest range of options for bands, second it is mechanically very simple (no motors to jam or burn out), and third it removes the need for a reflective ground plane beneath the antenna, so you can place it almost anywhere on the vehicle. The whip is an end-fed antenna, the tuner simply needs grounding to provide the return path for HF. So that is what I have on my vehicle, and it seems to work well (now I have sorted out the shorting issue, which was simply using the wrong gauge wire between tuner and whip). If I want a lower band, I simply park up and attach a longer wire to whip, suspended from a convenient high place. I know that apparently contacts aren't a good indicator of performance, but I have been able to speak to California from the Swiss valleys, using just my 100W radio, tuner and 2.4m whip combination, and my audio quality has been frequently remarked upon positively.
Well, how about the tuner itself? It either has motors (typical military configuration), or relays. You're partially correct about why the military uses tuners, but it isn't for simplicity or failure possibilities, or even efficiency. The term is ruggedness.
I've never seen a military tuner with motors, it's all solid state/relays (at least British Army), but yes, ruggedness is also a big factor (I didn't actually mention failure possibilities, and a solid state tuner is a great deal simpler in operation, if not design/construction than a screwdriver). And given that I drive an off-road vehicle, that's quite important to me
My point however stands: there ARE good reasons to use a tuner in a mobile application.
I've no problem with constructive criticism - However broad statements that have no substantiation or base in fact do tend to make my skin crawl a little regardless of where they come from. Oh - and to remain faithful to the original thread - I still prefer the IC 7100
Interesting - I'd like to see the date that ad was released. The prices are sick. Still curious about the different methods of matching and what happens to the match when I change antennas.
The question was never about tuners. Ifyou like the 7100 get it. If you like the 7k get it. If you like anything get it. Best advice is not to look for advice here on what to by. Go to a store and play with it and see if you like it, if not, then you will have no regrets and be rightfully informed. If you can't go to the store then know that the IC7100 has a horribly boring looking and quite archaic touch screen interface. Why did they not just charge $50 more and put a color screen in blows my mind. Also there is no video out which is kind of a dangerous ordeal when driving down the highway trying to manipulate radio settings. Additionally how long is D star going to remain in use? I don't know but it sounds awful to my ears and is not true Ham Radio. I guess the internet is acceptable to all the VHF junkies out there. I don't blame them. VHF repeater work is about as boring as watching tectonic plate movement from your backporch. To each their own. All I ever hear on any repeater anywhere, D star included, is weather, what you had for lunch, and I'm at the QTH so I gotta go- 73. I like my radio waves to propagate thousands of miles completely disregarding repeaters and internet ala HF. And I like long big group rag chewing. I cant stand the forced round robin style repeater operations where you have to wait your turn to speak. I want to just key down and talk as long as no one else is talking. HF is truly wonderful compared.
Up to you but I would never buy the 7100. The FT857D is also a rugged choice albeit to me the rx is a little too hot on noise and not audio and the AF dsp is absolutely non comparable to the quality of IF. But I know that the OP didn't ask about Yaesu.
If we keep in mind, that any HF mobile vertical can be tuned with nothing more than a simple shunt coil, it is possible to match a series of monoband antennas without changing the shunt coil. The exceptions are....
160 meter antennas are almost in a class by themselves. Depending on length, from 600 to as much as 750 uH of inductance are required. This fact lowers the Q almost no matter how we design the coil, so a separate shunt coil is required, and in most cases, no shunt coil.
Case two, is using a combination of antennas, like a few hamsticks, and a couple of Hustlers. That makes (a single) shunt coil matching a bit difficult.