SMA female to FME male adapters. Too much HT twisting?

[RenoHuskerDu]

Just about to order a dozen Larsen NMOKHFUDFME cables (NMO roof to FME) for a small fleet of vehicles. We'll be running Kenwood 45watt mobile radios in mgmt trucks (I'll go FME to UHF on those) and workers will plug their 8watt GT3-TP HTs into the antenna cable via SMA female to FME male adapters. (click here for sample from Lex Bezoszon, oddly I could not find any on antennafarm).

I got to thinking, there is no quarter-turn connect in this setup. Workers will have to wind their HT onto the SMA female side of the adapter. An that's after they unscrew their 20" whip antennas. What if I were to put an SMA/BNC adapter on the SMA male of the HTs, then another BNC on the FME that terminates the cables? Too much loss? Workers would still have to unwind the whip and screw on the BNC adapter when they get in the vehicle. Might want to just leave an HT on that cable in the truck at all times. and another HT on their belt. The Baofengs don't break the budget, I consider them semi-disposable, but keep my Yaesu HTs in an EMP box.

Maybe I'm overthinking this all, and should just make sure everyone is duty trained on how to put their HT onto the coax cable. Twist, twist, twist.

 

[mmckenna]

I dunno, I may be a bit biased, but this sounds like a really bad plan.

I've only used FME adapters in one situation and that was 20+ years ago. It's a fixed installation, not a vehicle, and was OK, but as soon as I could, I replaced it with the correct connector.

I know you've heard/read it a hundred times before, but adapters and HT's lead to issues. They put a lot of strain on the antenna connector on top of the radio. That usually results in the solder joint failing, which won't be evident to the end user. The radio just won't work. That might be fine for hobby use, but for any sort of commercial/public safety application, that's a bad, bad thing.

For the mobile radios, the FME's can work if everything is well secured. Still not ideal, and I'd encourage you to get the NMO mounts and the correct connectors. Unterminated coax is easier to install, and putting your own connectors on isn't really that difficult if you practice on some scrap cable.

For the portables, that sort of makes me cringe, a lot. It's a $40.00 radio. I'd push to get mobiles properly installed, or you will have endless complications. Users will screw it up. The radios, if unsecured, are going to be a hazard and you'll have failures. Failed radios, especially when not obvious to the end user, are worse than no radio, since there is a false sense of security.

Some Motorola HT-1000's with MTVA adapters are a good solution since it makes it pretty much fool proof (pretty much).

I know budget may be a challenge, and you have to work with what you've got, but after doing this for 30 years, I don't see it ending well.

 

[hill]

I also don't see the baofengs working too well with the power if just using the battery. Maybe you have adapters to power from the vehicle. I agree with all the time and effort spent getting these radios to work you most likely could have a mobile in each vehicle for not more money which would work better.

 

[mmckenna]

I can attest to trying to use a portable radio in a moving vehicle connected to an external antenna.

It's a hot mess.

Dealing with the cables, gonna be a mess. That antenna connector is going to get torqued all over the place.
The cheap connectors are only good for so many cycles, the cheap gold plating flakes off.
Constant flexing of the coax-connector joint will result in failure.
The antenna jack on top of the radio is going to fail. It will. Might not be today, but it will happen.

The audio output from the speaker will be too low and result in user frustration. It'll be hard to hear traffic, even if using a speaker mic. You'll need to have the speaker right up to your ear, even then clarity will suffer due to the small speaker.

Trying to drive while holding that radio/coax up to where the audio is actually any good is a hazard and will just put more strain on the jack.

My brother ran his ham radio like that for a while. It sucked for him. It sucked for everyone else having to listen to him. It sucked.

But, I've said my piece. You choose what's best for you.

 

[RenoHuskerDu]

I should have mentioned that the Kenwoods are not easy to come by at a decent price, but the long term plan is one in every vehicle. What's described above is an interim solution. Soldering on cable ends is not challenging to me anymore. Maybe I'll just solder SMA females on the coax and run that way for now. The only break I fear is the antenna jack on the HT. We haven't broken one yet although workers have broken several whip antennas in drop events (side note, GT-3TP hi-cap batteries have weak solder conx inside that fail on a drop event, just open case and resolder). Remarkably, no Baofeng has yet failed in 2 years. One arrived DOA.

Thanks for the feedback. I ran my Yaesus that way, years ago, but I used an earpiece/mic. The remark about hearing the speaker is useful. With coax on the HT that will be difficult indeed.

 

[mmckenna]

Solder/crimp is the way to go. There are some inexpensive coax crimp sets out there that work fairly well. Adding marine grade heat shrink tubing over the crimp really helps with durability. But having to spin the radio on each time is going to get old. There was some benefit to the older radios that used BNC connectors.

As for used radios, not sure what band you need, but there's some good options out there if you shop around:
Motorola CDM-750
Icom F-320S, F-420S, F-221, etc.
There are periodically good deals on Kenwood TK-x180 radios if you keep your eyes open.
I used to pick up VHF CDM-750's for anywhere from $50 to $100 bucks. Still running a few of those at home.

I know it's a challenge doing this stuff on a budget, but the right gear really pays off in the long run. Less failures, better audio, better performance.

 

[RenoHuskerDu]

SNIP
There are periodically good deals on Kenwood TK-x180 radios if you keep your eyes open.
SNIP

Found and bought two Kenwood 8180HK2 up in Canader last month. Keeping an eye on that fleabay vendor, he said he gets in sets of them every few montths.

 

[mmckenna]

Found and bought two Kenwood 8180HK2 up in Canader last month. Keeping an eye on that fleabay vendor, he said he gets in sets of them every few montths.

Good deal. I bought a TK-7180 late last year for $100.00. Turned out to be an old UPRR railroad radio. Tuned up nicely on the service monitor. I installed the KRK-10 remote head kit and installed it in my wife's new truck. If you just need analog, those are solid radios.