Okay so the previous post in this series may have been a bit TOO ambitious.
New Plan
This past weekend, I was bored (like I always am) and it was way too hot to do anything actually meaningful. So off to Google I went with a pocket of inspiration.
We're planning to leave for vacation in the next few weeks and while I will be taking my Baofeng with me, it got me to thinking...how much more cooler could I make the Baofeng?
The answer is yes, and the cool factor comes from this fellow who doesn't live too far away from me, in Raymore, MO.
Now THIS IS COOL! The full video is here.
Phil Frame, KF0LHD, shows us that with a Baofeng, a battery, and one of those neat military handset receivers, you can create THE ultimate, self-contained Baofeng-based Hammo can which will last for days, is truly portable, and can be created with the cheaper and smaller 30 caliber ammo cans.
So off I'm setting now to build my own! Sadly, it won't be done before vacation but that doesn't mean I can't take it next time or anywhere else I may go on the go!
I'll base my design off of Phil's design, but add on my own twist - I'll be reusing and fabricating a PTT button into an old landline receiver instead of purchasing an off-the-shelf one for the Baofeng.
The only thing that will need drilled into is the lid. Any holes that I drill out will be waterproofed with rubber washers, epoxy, etc. I'll only need to drill out 3 holes - one for the mic plug, one for the power switch, and one for the antenna connector.
Fabricating a Phone
In the video, Phil uses an off-the-shelf speaker microphone that looks like a military handset. While this is cool, I think it'd be even cooler if I made my own!
Here's the plan - we know that the Baofeng triggers PTT by shorting both grounds together:
The internals of a phone receiver is pretty basic - a speaker plus its ground and a mic plus its ground sent to an RJ11 4P4C jack. 4 connections, 4 straightforward connections, that is.
For the Baofeng, we only need to modify the handset to accommodate the PTT button, which will short the speaker ground and mic ground together when the PTT button is pressed. You can configure the GX16 mic plug in any form you want - just make sure to use MIC+, MIC-, SPK+, and SPK-, and don't forget a momentary button between SPK- and MIC-! Also remember the pinout as well.
The Lid Layout
The lid will contain the antenna connector (an SO239 or BNC, whichever you'd like or can adapt better), the 4 pin microphone connector, and the on/off switch. Not too terrible. I've rendered a prototype of what I'd like the layout on top to look like.
This should provide me with enough clearance for the handle as that's actually the bigger issue. The handle is somewhat large but I don't think it will cause any issues with this layout.
Wiring will NOT be a PITA this time. Here's a diagram below:
Not much to it - 3 pieces of wire at least. Now you could add stuff to it like a voltmeter*, ammeter, etc., but I found that to be a mess of wires when I built the original Hammo Can. Less is best, yknow? You'll want to ensure your switch is waterproof or weatherproof if you plan to use it outside - I plan to. Don't forget dust caps either - you don't want your antenna or mic plugs to corrode!
* As a bit of an anecdote, I found a hidden secret within the UV5R! I've had this thing for almost 10 years now and just realized that if you hold down 0, it displays the battery voltage for about 2 seconds! Really handy and saves you from having to buy a voltmeter.
I also ran into an issue - battery eliminators for the UV5R are all linear, meaning that excess power gets dumped off as heat. Now for some of you this may not be an issue as Baofengs are cheap, but I'd REALLY like to keep this device working for as long as I can get it, and excess heat in an enclosed area is never a good thing.
So I want to open the eliminator, score a free 7808, and instead insert a small adjustable switching buck converter set to 8.4 volts. Problem solved - no heat, no problem. At VHF/UHF FM frequencies, I'm not too concerned with switching noise. Anything to prevent an unnecessary fire is a win for me.
EMCOMM Ready
Besides 2 meters and 70 centimeters, this radio can also function as a weather radio. I would STRONGLY ENCOURAGE you to program all 7 weather frequencies into your radio. I'm a huge proponent of NOAA Weather Radio, and one day, it could save your life.
There has been legal dispute as to what else you can use this radio for. Set on low power (1 watt), you could use it on MURS (151MHz) or FRS (462MHz). If you're licensed, why not GMRS? Here's why it's okay to monitor but terrible to transmit on with this.
First, MURS and FRS have strict requirements on removable antennas. They aren't allowed. Period. Second, the Baofeng isn't a type-accepted radio for these other services, meaning that if you're caught using this on the aforementioned bands, you'll most likely face punishment. So just don't do it. You can monitor, just don't transmit.
Regardless, this would be a very useful and utilitarian device to use in an emergency situation. With even more engineering, this would most likely do well as an EMP-hardened radio set. I might consider doing this later on, but for now, I'm okay with using this radio as is. The waterproofing and sealing of this kit means that you could use this for tornado search-and-rescue, hurricane relief, or any other weather-demanding situations where local communications are crucial. You can also stay informed by using the Baofeng's built-in FM radio as well!
For these reasons, I think I could classify this as an EMCOMM-ready kit. It's durable, versatile, and simple to repair out in the field. I might make a bigger one actually with the 50 caliber box, and this could have the QYT in it or a higher-powered (20 watts or more) radio. Of course at that point, an external antenna off of the box is a must - you don't want RF blasting back in your face, despite RF being non-ionizing radiation.
Did you know RF can actually blind you? Since our eyes have no way of dissipating heat, it is the only tissue on the human body that is HIGHLY susceptible to high RF power and exposure. Sadly, carrots won't help.
CB Radio Edition
For those of you not (yet) licensed, fret not!
I suppose one could make this for CB radio, especially with the mini models that have hit the market in the past 10 years, like the Radioddity CB27, the Cobra 19 Mini, and other compact radios going around. Heck, even my AnyTone SMART-10 10 meter radio could work very well in one! Not much would need to change actually, and I would think that these models would still fit in the 30 caliber can, along with the battery and microphone. It would be especially helpful if you used a remote CB model (such as the Radioddity CS47 or Cobra 75) which has controls on the microphone. Even the models with the basic UP/DN controls on the mic would be a start, like what's on the CB27 model. The perk is that you wouldn't even need a buck converter either, and since it's HF, skip is certainly possible!
Below I've sketched a design of the lid and the internal arrangement. I've removed the I/O switch as the most compact models already have an on-off switch on their volume pots. To allow for a removable microphone (if you'd like on the CB27 or AnyTone), just take apart the mic, cut (personally I'd desolder) the microphone at the mic end, solder that end to the 4 pin plug on the lid, and then salvage another 4 pin Cobra or Midland microphone cord to attach to the microphone capsule! Problem solved!
Of course, the antenna would most likely need to be mounted remotely. On this design, it shouldn't be a problem - just hang an antenna in a tree or put up a 1/4 wave vertical and run a bit of coax back to the box!:
If you want the entire radio to be self-contained (which I'll most likely do with the CB27-type model), I'd recommend leaving the lid blank and installing everything inside of the box like this:
This might be my next move for my cousin as well as myself. I've told him that I want to build him a go box for CB, and it would give us a way to communicate with one another. And since he has an Antron 99 mounted outside his window, imagine the possibilities for him!!! For me, I'll probably build this version for 10 meter AM/FM operations, and use some form of a manpack antenna. Come to think of it, Peter, VK3YE has a video up where he made a nice antenna from a 6ish foot fishing pole that can work on 5 bands that includes 10 meters (I imagine 6 if you count 11m/CB)! I'll most likely follow suit, but make one that's tuned for one band in the middle of the 29MHz sub-band. AM and FM communications are popular up here.
If you want weather monitoring capabilities, I'd purchase an emergency AM/FM/WX wind-up emergency radio and stick it in this version of the box. Not really convenient, but it'll do.
Stay tuned for the photos!!!
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