Radio Options for a Mobile Installation with Amperage Limits

One question recently brought up to me was the solution for a mobile install into a small car with a small alternator. Not wanting to run a full setup for fear of over-drawing the system.

First off, I want to say that no matter what solution – if you install a mobile radio, please run fused, proper-gauge wire directly to the battery. Don’t try any shortcuts here – they will only cause problems later.

Second, I am a huge proponent of using equipment for what it was designed – but I also do understand budget and creativity will sometimes break that rule. In this case, a mobile radio used in a mobile install is almost always the best. Mobile radios are designed with (usually) larger screens, bigger knobs, and other mobile-oriented features. Fumbling with a small HT in a car is no better than texting on a cellphone – don’t try it!

So for my solutions:

Solution 1: Get a 50W Mobile Radio.

I personally would go with a full powered mobile radio and program the power output to 25w or less. At 25W or less, most will not draw more than 5 Amps on transmit. In fact, I already do this and always have my radio set to 10 or 20w, and only use 50 if needed.

TYT TH-9800

Why? I would much rather have full power available if needed, and full-power, readily available mobile radios are easy to obtain. Some will also will have features such as cross-band repeat and dual VFOs

Depending on if you want single or dual band, these can be had new for around $160 (QYT KT-980). However, I would bump up to $210 for the AT-5888UV or $260 for the TH-9800, which have remote heads – great (necessary?) for a smaller car.


Solution 2: Get a 25W Mobile Radio.

Something cheap like the dual-band QYT KT-8900D are 25W and use less than 4 Amps to transmit on high.

However, you lose options such as a remote head, and ability to punch the power output in an emergency to 50W. You also lose some features, at least with this unit, such as Cross-Band Repeat.

QYT KT-8900D – Yes, Its Tiny!










Solution 3: Get a Name-Brand HT (Yaesu, Icom, Kenwood).

Yaesu FT-65R

With the name brand radios, you can plug 12v into the side power port, and at 5W max, will use very little power. When you do so, the radio will charge its battery and you can use the radio. When you turn off the car, the radio will stop charging, but will remain powered on and will run off internal batteries. This is one “feature” that pushed me to upgrade from a Chinese radio. I don’t want to have to swap out a battery eliminator for a battery each time I get in and out of the car – and I also want to be able to charge my battery whenever in the car easily.

However, you need to find a way to mount a handheld, buy a microphone, buy SMA adapters. You also lose the “designed to be mobile” features such as an easy to see display and big knobs. On many newer HTs, the volume or squelch control is not physical. You must change with buttons or a menu.
When I used an HT in the car, I would have to pull over to change frequency, because the screen and knob were so small. Not to mention the several-minute process to dismantle the mount, antenna, microphone, etc whenever I went to leave the car.

You can get a single band HT from Yaesu for $90 new (FT-25R) or dual band for $120 (FT-65R). Both are on sale at HRO, and seem to be on sale often.

Normal prices vary, but seem to be about $20 more on average. Hand mic and DC power adaptors are extra.