Building a Portable Box for MXT500

[WRDJ205]

I've tred searching the myGMRS foum for this topic so fogive me if it's been done before (if so, I would appreciate the link)...

I'm interested in building something similar to the Midland ammo can but much simplier.  I'm thinking of using a hard plastic case (think Pelican knockoff) that would hold the radio, mic, antenna and a power supply.  I would be taken out and set up for use in the field.  Primary use would be to make it mobile enough to grab and use as a base or in a vehicle, UTV, tractor, etc.

For power, I was thinking something like a 155Wh portable power station that would fit inside the case.  I don't know if I can post links but there is one on Amazon that would fit well.  But, this would mean i need an AC to DC adapter.  I would like to be able to charge off of solar as i already have foldable panels.  

I haven't purchased the radio yet so I don't know the actual power draw other than what is published in the Midland literature.  

Has someone done something similar?  Any advice to someone just getting started?  

[Socalgmrs]

there are many many videos and what not about this type of thing.   Getting a good enough antenna up high enough is always the problem with anything portable.  Also the battery life is a problem.  Adding a solar charger would help with that but adds bulk.   A hand held and a good external antenna can easily do 30miles maybe more depending on many factors.  The weight and size of a radio in a box with antenna and cable is not something you want to carry for long in an evac situation.  

[WRDJ205]

Thanks for the reply.  Right after I posed the question, i found the right terminology to search.  "emcomm box" seems to show up a bunch of videos.  guess i have some watching to do.  

[gortex2]

As said do some searching. We have done this for years for SAR stuff as well as other EMO related boxes. Currenlty we have 2 in harbor frieght peican cases. One is a repeater and one just a mobile with mag mount and cirgarette lighter plug. We also have 2 in Plano tackle boxes. 

[Merky1761]

Here’s mine that I am almost finished with.  MXT 500 in a Harbor Freight Apache 3800 case.  Microphone and power cords ect  go inside the Tupperware. It’s powered  off of a 12 volt power supply at the house and a 10ah LiFePO4 battery when in the field. Waiting on a solar battery charger and a few other things 

[WRDJ205]

Merky1761 what radio are you using? Has that battery held up well for you?  

[Merky1761]

Midland MXT500. Battery is doing fine so far, I have only had it out twice so I can’t comment on longevity. I have left it on at the house for two days and it was still at  13.4 volts.    I’m looking to put a small solar panel and charger with it. 

[WRHS218]

20 minutes ago, Merky1761 said:

Midland MXT500. Battery is doing fine so far, I have only had it out twice so I can’t comment on longevity. I have left it on at the house for two days and it was still at  13.4 volts.    I’m looking to put a small solar panel and charger with it. 

You do nice looking work!

[WRXB215]

@Merky1761 That looks like a very nice project. Congratulations. 

[Merky1761]

It was a project, the designed changed many times.  

[WRDJ205]

That’s a good looking set up.  I’m going back and forth on the Midland MXT500 or the Wouxun KG-1000G Plus.  Plan to have an assortment of connection cables to be able to power it from different sources.  But also to have an onboard LiPO4 battery and AC power supply.  

[Merky1761]

1 hour ago, WRDJ205 said:

That’s a good looking set up.  I’m going back and forth on the Midland MXT500 or the Wouxun KG-1000G Plus.  Plan to have an assortment of connection cables to be able to power it from different sources.  But also to have an onboard LiPO4 battery and AC power supply.  

Thanks, I was looking at the 1000G also and decided on the MXT500 for simplicity and the waterproof rating.  

[WRDJ205]

What dc power supply are you using ?  What amperage?  I keep reading that I need 30a.  Would like to get a compact one that I could fit into the case.  

[WRYZ926]

A 20 amp power supply will be more than enough for the MXT500 or any other 50 watt radio as long as you running just one radio. The power draw of the MXT500 is around 12 amps while transmitting on high power.

Remember that most power supplies are rated for their maximum amp draw. Their continuous power rating will be lower. Most 30 amp power supplies are rated at 20 - 25 watts continuous. 

Basically one can run between 75% to 80% of the rated amps continuously.

[Merky1761]

1 hour ago, WRDJ205 said:

What dc power supply are you using ?  What amperage?  I keep reading that I need 30a.  Would like to get a compact one that I could fit into the case.  

Jeversity SPS-1330

30 A max

25A continuous

[WRYZ926]

A 30 amp power supply with 25 continuous amps is enough to run two 50 watt radios on high power at the same time. A 30 amp power supply with 20 amps continuous will not be enough to run two radios simultaneously on high power.

I run my TYT TH-7800 and Wouxun KG-1000G on the same R & L Electronics 30 Amp (22 watts continuous) without any issues. Though I only run mid power level on both for the repeaters and don't transmit on both at the same time.

[warthog74]

You could save some money and use a lower powered radio. Wont need as big of a battery or a higher wattage solar panel. For instance my recent simplex repeater build has been running for a few weeks now on a measly 6ah battery and 10 watt solar panel. However my radio only draws 1.5 amps at 10 watts while transmitting, and .3 amps when idle. Here is the link if you want to see what i used and how it turned out. Might help give you some ideas.

 

[WRDJ205]

On 3/27/2024 at 10:32 PM, warthog74 said:

You could save some money and use a lower powered radio. Wont need as big of a battery or a higher wattage solar panel. For instance my recent simplex repeater build has been running for a few weeks now on a measly 6ah battery and 10 watt solar panel. However my radio only draws 1.5 amps at 10 watts while transmitting, and .3 amps when idle. Here is the link if you want to see what i used and how it turned out. Might help give you some ideas.

 

That’s a good idea.  Since I plan to use my set up for both a base station and keep it portable I was focused on the higher output radio.  
 

I’m cutting my teeth on this one but I see a small more compact setup for a second vechicle not too far in the future.  

[WRDJ205]

Ok.  So after more research (and the fact that the 1000g plus is out of stock) I’m looking at shifting gears to the Radioddity DB20 or KG-XS20G.  
 

The only drawbacks I can see for my application is that the receive only frequencies are less and the lower output (appears that it’s worth trying the lower watts based on some other threads).  

Is there any significant differences in programming?  Anything else to consider?  
 

 

[WRDJ205]

Still working on it but getting the pieces and parts together.  Going to program repeater frequencies this weekend and see how it goes.  
 

I’m getting 12.5v from the power bank.  Definitely enough to power it for RX and TX.  Not sure if it’s impacting the radio transmitter power though. 

[WRYZ926]

The Wouxun KG-XS20G does very well in my SxS with a Comet  2x4SR antenna. I get excellent signal reports  when talking through the repeater 21.5 miles away. 

I picked up an Apache hard case from Harbor Freight today. I am going to use it for a go box for my Xiegu G90 HF radio and might see if I can fit a KG-XS20G in the case too.

[WRDJ205]

I still debating on if I use the case as a transport medium or if I put in partitions and make it more customized.  
 

Right now everything fits snuggly and doesn’t bounce around.  I never planned to operate in on the box.  I may even have room for my handhelds.  
 

Still need to figure out the various power config pigtails I want to include. 
 

i’m using a midland mxta25 ghost antenna.  Didn’t have a chance to test range yet but hope to this weekend.