Radio Preppers

General Category => General Discussion => Topic started by: gil on July 16, 2015, 03:07:29 AM

Title: Ultra Portable Radios.
Post by: gil on July 16, 2015, 03:07:29 AM
Hello,

I have been thinking that what I am most interested in isn't truly QRP, but ultra-portable radios (UPRs?). The definition of QRP is a power limited to five Watts in CW or ten in SSB. You can reduce power on a rig the size of a washing machine connected to a five-element Yagi and still be QRP. My favorite radios have all been QRP, but only because of their size. What I really want is something I can carry in a backpack, or even better, in a coat pocket. I'd be happy to have a twenty-Watt CW radio that fits on the palm of my hand. The only problem would be the transmit current draw. Ultra-portable means that the battery has to qualify as well.

A UPR would need to be very small; no bigger than an Elecraft KX1, which would only qualify because the case has space for batteries. I can think of the Weber MTR as the best example, or a Rock-Mite. Any mode can qualify as long as the radio is small enough. I would not include radios that can't work without a computer. The typical power source would be eight AA cells or a small 3S lipo pack.

Surface-mount components have made the impossible possible, and we haven't seen the last of it. Designs will only appear however if there is a demand or at least some interest. Hence my reason for writing this.

Looking at Youtube videos of emergency communications setups, I mostly see "go-boxes" the size of a small fridge powered by a big battery or a generator. That is great for community support with some kind of an infrastructure in place or for a short duration, such as we've seen with Katrina or Sandy. However, when it comes to individual communications, we only find VHF/UHF handhelds. I believe that there is a place for long-range radios that fit in a bug-out bag without being felt. There is no need in our case for a power limit other than dictated by portability and air time.

Let's make a list of available UPRs, just for kicks!

I nominate the KX1 and the MTR. What else?
Title: Re: Ultra Portable Radios.
Post by: Greywolf69 on July 17, 2015, 05:04:04 AM
If you want real URP you need to build your own, there are plenty of matchbox QRP rig designs on the net. Small enough to fit in an altoids tin (inc. battery) the antenna is then the bulkiest part of the setup.

Your thread reminded me of an article in a radio com magazine back in the 80's, wish I could remember which one because the article had circuit designs and )to me) it looked like a clean and uncluttered build.

Oh, I did a diploma in Rad-comms back in the 80's and still find circuits "pretty" when they are right ;)
Title: Re: Ultra Portable Radios.
Post by: gil on July 17, 2015, 08:56:17 PM
Indeed, most come as kits.. The Weber MTR though is now sold by LNR Precision, but I can't think of any other that come as a pre-built radio.. One doesn't need to be an electronics guru to build one however, and you can learn soldering in ten minutes. Being very meticulous should produce a working radio the first time power is applied. If there is smoke though, that's when the "fun" starts. I would suggest anyone to start with an easy kit, like a Rock-Mite. In any case, the quality of the manual will in great part determine chances of success. The best manuals and kits are from Elecraft, hands down. Having to build a radio shouldn't be seen as an obstacle, and learning some electronics goes a long way towards self-sufficiency.

Gil.
Title: Re: Ultra Portable Radios.
Post by: Greywolf69 on July 18, 2015, 12:15:21 AM
Don't release the magic smoke!
I used to spend hours soldering  for someone else. Now it's time to do it for me :)
Title: Re: Ultra Portable Radios.
Post by: Wayne on May 18, 2016, 05:59:31 PM
Hi Gil,

I took your post of a year ago as a challenge to be met :)  The result is pocket-sized: the Elecraft KX2. It's the size of the KX1, but covers 80-10 m, with SSB/CW/data modes, and has 10 watts output. Most of the same features as the KX3 at a much lower price. Current drain is about as low as physically possible with 32-bit DSP -- 135 mA minimum with the preamp and backlight off.

You can use it table-stop or hand-held, like an HT, with a whip. Has an internal wide-range ATU, internal 2.6 Ah Li-ion battery, built-in mic and speaker. Weighs 13 oz. less battery. 1.5 x 2.8 x 5.8".

Be happy to have you try one.

Wayne
N6KR


Quote from: gil on July 16, 2015, 03:07:29 AM
I have been thinking that what I am most interested in isn't truly QRP, but ultra-portable radios (UPRs?). The definition of QRP is a power limited to five Watts in CW or ten in SSB. You can reduce power on a rig the size of a washing machine connected to a five-element Yagi and still be QRP. My favorite radios have all been QRP, but only because of their size. What I really want is something I can carry in a backpack, or even better, in a coat pocket. I'd be happy to have a twenty-Watt CW radio that fits on the palm of my hand. The only problem would be the transmit current draw. Ultra-portable means that the battery has to qualify as well.
Title: Re: Ultra Portable Radios.
Post by: Sparks on May 18, 2016, 06:52:22 PM
I was composing posts on the Elecraft KX2 while Wayne posted the foregoing:

http://radiopreppers.com/index.php/topic,1098.0.html (http://radiopreppers.com/index.php/topic,1098.0.html)
The Elecraft KX2 will be announced this week (May, 2016 (http://radiopreppers.com/index.php/topic,1098.msg10748.html#msg10748)
Title: Re: Ultra Portable Radios.
Post by: RadioRay on May 18, 2016, 06:56:42 PM
UPR is the next iteration of the Trail Friendly Radio revolution. 

Wayne, good to see you here. Looking at the KX2, I think you really are filling the void for a high performance, yet field friendly HF rig.  When they become generally available, I'll likely put it right next to my well worn Wilderness Sierra - still going strong after all these years.

- Top mounted controls. ( In thousands of trail miles, I've usually operated from the ground, so a 'shelf friendly' design is no friend to wilderness ops.

- Small enough to take with you. (A watertight hardcase would still be something I'd find and buy.)

- =<10 Watts with built-in ATU.  (Few cables and connectors to go wrong.)

- General coverage receiver!

- 60 and 80 meters for NVIS duing solar minima.

I found this link: dream fuel for go-anywhere radio nuts like us.


https://drive.google.com/file/d/0B4hTm2wk0Fk8aUNqaUtrWmM3bHZlQVBIZFZmMXMzY3UxM21j/view?pref=2&pli=1 (https://drive.google.com/file/d/0B4hTm2wk0Fk8aUNqaUtrWmM3bHZlQVBIZFZmMXMzY3UxM21j/view?pref=2&pli=1)


73 de RadioRay  /..._  ._

Ps. What's a "microphone" ?  I've heard of them, but can't seem to remember what they're for.   ::)
Title: Re: Ultra Portable Radios.
Post by: cockpitbob on May 18, 2016, 08:58:42 PM
Wayne, welcome aboard.  Check back in from time to time  ;D

Only a lack of spare time has stopped me from buying an FT-817 so I can do digital as well as all modes and bands.  I'm glad I waited.  The KX2 just bumped the 817 off the "soon as things slow down" list.  I think my MTR-3B and a KX2 will fill all my QRP needs and I can dump my other 3 QRP rigs.  ;D
Title: Re: Ultra Portable Radios.
Post by: gil on May 19, 2016, 03:44:16 AM
Wow! Thank you Wayne! You probably just sold one.. When can we know more and see photos? Hell, I'd love to beta test one, but don't expect to get it back ;-) just a check, LOL. I built a K2 and K1, even bought a KX3, so, pretty please, being the inspiration and all..

Gil
Title: Re: Ultra Portable Radios.
Post by: gil on May 20, 2016, 03:21:31 PM
There it is, Steve WG0AT got one...

https://youtu.be/2CyCoqBhlCQ

I'd say the KX2 qualifies as a UPR, barely, because of size. It certainly exceeds my hopes as far as features. If it is as good as the KX3 then Elecraft has another winner. While not ultra small, the size difference with the KX3 seems significant. Glad it retained the same excellent display.

I sold my KX3 because I needed money but also because I was only using a fraction of its capabilities. The same would probably be true of the KX2 but in time I would get nearer its full potential. The K1 to me was a near-perfect radio with the four band module. A K1 with SSB and 80m would have been ideal. Technology advances rapidly though and the KX2 is the result.

QuoteBe happy to have you try one.

Wayne, I just emailed you my address! I'd do a review in French too, and what a great excuse to take the train to the Alps and try SOTA...

Gil
Title: Revolution: Ultra Portable Radios.
Post by: RadioRay on May 21, 2016, 11:24:17 AM
! QRP Comrades !
Join The UPR
Revolution !




From each according to their power budget
, TO each according to their gain/noise figure.


Radio for the proletarriat.... pro-li-tariyat.... uh. ..... for the little guy!

Title: Re: Ultra Portable Radios.
Post by: gil on May 22, 2016, 04:12:38 AM
Ray, the photo isn't showing...

Gil
Title: Re: Ultra Portable Radios.
Post by: RadioRay on May 22, 2016, 10:33:50 AM
I've inserted a few QRP REVOLUTION! attachments.  Click to enlarge.  Evidently, qrz.com blocked linking to my pictures there. I can understand that - it's their site.

>Ray
Title: Re: Ultra Portable Radios.
Post by: gil on May 22, 2016, 02:40:20 PM
Excellent Ray, albeit slightly scary ;-)
Mind if I share those images?

Gil
Title: Re: Ultra Portable Radios.
Post by: gil on May 22, 2016, 02:44:08 PM
Beyond QRP, where size only matters, Ultra Portable Radios!
Title: Re: Ultra Portable Radios.
Post by: Rescue9 on May 22, 2016, 06:43:49 PM
I'm with you Gil on the small size versus small power. I want something that I can take anywhere, hence the prepped part of our forum. As a fire / rescue guy, I very much understand the need for a portable, real-world emergency comm setup. It is one of the reasons that I built the m0nka radio; small package, big possibilities.

Seeing the new KX2 has me drooling though. I simply have to make this part of my EDC bag. Now all I have to do is find the funds... no small task on a city government employee's paycheck.
Title: Re: Ultra Portable Radios.
Post by: RadioRay on May 22, 2016, 07:16:03 PM
Sure Gil -

Feel free to use them, and maybe they could be used for T-shirts and coffee cups to generate a little income for this site :-)


>Ray

Ps. Right now, I am looking at your former MTR2b and at a small, German tobacco (a) tin and getting ideas for my UPR.

(a) - Reiner Professional.  German made, in a Danish style. 
Title: Re: Ultra Portable Radios.
Post by: gil on May 23, 2016, 04:24:03 AM
Thanks Ray.

I wish I knew enough or had time to learn radio circuit design. We need a circuit designer on this board! We'd get something cool going and make kits. I'd  start with a single band CW radio with a  20W output but low current draw on receive, regular VFO, a 500Hz filter and the ability to dial down power to save batteries once a contact is made. A bit like a Rock Mite with a VFO and on steroids, with a DFE (direct frequency entry) like on the MTR, what a stroke of genius that was, and no need for a display, which is only useful to go to a sked frequency. But that would imply a DDS VFO, oh well, if Steve Weber can pack a three band rig with DDS and a microprocessor in an Altoids box, anything is possible. And while we're at it, add a Bluetooth chip. I think radio designers all swore a secret oath to ignore Bluetooth..

Gil
Title: Re: Ultra Portable Radios.
Post by: vwflyer on May 25, 2016, 08:46:16 PM
QuoteI think radio designers all swore a secret oath to ignore Bluetooth..

Wouldn't a KX2 with bluetooth and a dedicated PSK/RTTY IOS/Android app be the perfect paring? You wouldn't need to use the paddles to send digital and non-CW proficient people could have a portable and easy text entry device.
Title: Re: Ultra Portable Radios.
Post by: gil on May 26, 2016, 03:41:11 AM
Definitely. You could also use Bluetooth headphones. Bluetooth paddles would appear, and all kinds of neat things.

Gil
Title: Re: Ultra Portable Radios.
Post by: gil on May 26, 2016, 03:47:18 AM
One comment to Wayne: Why go with a proprietary battery pack? A 18650 cell holder would have been much better. I bet that's what's in it anyway. You lose one cell in the pack and the pack is gone.. Especially that the charger doesn't seem to be the balanced type. I'd put a 3x 18650 holder in it and be done with it. Maybe someone will 3d print one, or a holder shell to fit the KX2. 18650s now also come in 3400mAh.

Gil
Title: Re: Ultra Portable Radios.
Post by: gil on May 26, 2016, 11:11:44 AM
I am adding one more desired feature for a UPR... I have been looking at the Clansman PRC320.. What a beast of a radio! It sure isn't portable by our QRP standards, but I read a comment from a user who said his tumbled down a hill and fell in a river.. No ill effects! The case sure looks like you could run over it with a truck. So a sturdy case, if not watertight, at least weather resistant is a must. Good thing with kits, you can often choose or replace the case like Ray did with his KX1. Hammond makes great cast aluminum cases.. If I get a KX2, I will surely make a special bullet proof case for it.

Gil
Title: Re: Ultra Portable Radios.
Post by: RadioRay on May 26, 2016, 09:30:30 PM
Speaking of UPR's, I just received my MTR5b and WHAT a receiver!  I put it on the air on the home brew magnetic loop and right away K1A / Special Event Station in Texas for Memorial Day came back and about blew my phones off. When I told him 2 Watts - we was astounded.  Great propagation - to be sure. All this on a cheap RadioShack 9 volt battery.

I am already planning an "UpArmored" MTR5b in a waterproof case, much like my KX-1 was http://radiopreppers.com/index.php?topic=897.0 (http://radiopreppers.com/index.php?topic=897.0), but smaller, due to the relative size of the MTR. Rather than aluminum, I may use the 3D printer at work to make the faceplate to slide into the kayaker case - to maintain water seal.

73 de RadioRay ..._ ._  /shirtpocket portable

Ps. If ONLY Steve had designed in the general coverage receiver - it would have been perfect for a Morse-o-holic like myself, and many others.
Title: Re: Ultra Portable Radios.
Post by: Wayne on May 27, 2016, 04:39:24 PM
Quote from: gil on May 26, 2016, 03:47:18 AM
One comment to Wayne: Why go with a proprietary battery pack? A 18650 cell holder would have been much better. I bet that's what's in it anyway. You lose one cell in the pack and the pack is gone.. Especially that the charger doesn't seem to be the balanced type. I'd put a 3x 18650 holder in it and be done with it. Maybe someone will 3d print one, or a holder shell to fit the KX2. 18650s now also come in 3400mAh.

Gil

Hi Gil,

Good questions. Nice to see that the folks on this list have put in some serious thought on the topic -- as have we.

First, battery sockets take much more space than the batteries themselves; they're something like 120% of cell volume for a high-quality multi-cell holder, larger in all three dimensions. Worse: they're often unreliable at the high currents available from 18650 cells. The KX2 can draw over 2 amps in transmit mode, worst case, such as when pumping 10 watts into an ad-hoc field antenna that presents a very low-Z load. Even very high-quality holders have contacts that can migrate or distort under heating.

But we also didn't want to leave any aspect of our internal battery pack to chance. The cells we're using are 2.6 Ah and have an excellent track record (millions shipped by the manufacturer). They're double shrink-wrapped, and we had them use a serious, 5-amp plug, unlike some of the poor-quality 0.5 amp plugs you see on other packs. Inside the shrink-wrap is a circuit board that protects the individual cells against over-current, over-temp, and over- or under-voltage.

We also monitor all of these parameters in the KX2's firmware. For example, if temperature or current or SWR is too high, we roll back to a safer power level and stay there. If that doesn't restore target levels, we'll go so far as to exit transmit mode or even shut the unit off. It's all about ensuring safe, reliable operation for field ops. The user should correct the problem (say, by adjusting the antenna or swapping in a fresh battery). Only then can they increase the power setting again.

The matching charger was also carefully vetted. We've been using the batteries and chargers in-house since October of last year, just to be sure. Then we signed up half a dozen top-flight SOTA operators as field testers. They've been using the radios, batteries and chargers daily for over two months. Not a single issue.

One bit of trivia: We designed a custom nylon pull-loop to make it easy to unplug the battery pack's 2.1-mm barrel connector when the pack is inside the radio. The geometry is a bit tight.

Of course you can also plug in the pack externally. In fact you can have both internal and external batteries plugged in at the same time, and the radio will run from whichever has the higher voltage. Inside/outside connectors are diode isolated from each other with low-drop (0.1 V) battery-ORing diodes that were designed for this application. More important, this protects the battery from accidental charge by an unknown power source. (The pack must be charged externally, but this isn't a big deal, as it can be removed/installed in seconds.)

Wayne
Title: Re: Ultra Portable Radios.
Post by: gil on May 27, 2016, 07:07:26 PM
Thanks Wayne. Good call on using protected cells, which I guess is a simple solution to charging three cells in serie. I am using rechargeable AA cells right now but thinking of 18650s for a bit more capacity. I can charge them with a solar panel having a couple USB outputs and chargers like the XTAR or Nitecore. I will use protected cells as well, but in a holder. Less of an issue with an external supply.

I have used small LIPO packs in the past but I lost them all to bad cells when I inadvertently let them get too low. I suspect the small current draw sort of artificially kept the voltage higher than it would have been otherwise under a decent load, but still depleting the cells beyond recovery. Protected cells would have avoided the issue.

I have put the KX2 on my list of "wants." Worried about being charged VAT here in France. So it probably would have to wait. I'll have to rely on my MTR for camping this summer. I also want a RT-320, totally different animal.

I built a K1 and a K2, bought a KX3, and they were the best radios I have ever used. My only gripe with them has always been the lack of weather sealing. Nothing a Pelican case can't solve, but operating in bad weather is a no-no. No HF radio I know of offers that of course, but one can always dream.

I hope Elecraft is not leaving the kit market entirely.. I know, the K1, K2 and KX1 are still available, and I hope for a long time.

As long as I have you here, here is my issue with current QRP kits, of any make: They are either mostly CW rigs or SSB, and only a few of those like the Weber Suvivor, Iler or OzQRP. The SSB ones however either do not have CW or do as an afterthought, with no keyer or narrow filtering. I want a real CW radio kit that does SSB as well. A dual bander  would be awesome, or even a single bander. A single bander would sell like hot cakes because people are going to want more than one.. Anyway, I like throwing ideas around..

Congratulations on the new baby, it looks like a winner!

Gil
Title: Re: Ultra Portable Radios.
Post by: gil on June 09, 2016, 06:23:52 AM
Darn it... I'm so broke now, it's not even funny. I have a KX2 on order...

Gil.
Title: Re: Ultra Portable Radios// Survival Rig???
Post by: RadioRay on June 12, 2016, 02:09:44 AM
There is the " 1 Watter" which is gaining popularity.

URL:   http://www.kitsandparts.com/1watter-V3.php


Looks like fun!


de Ray  ..._ ._
Title: Re: Ultra Portable Radios.
Post by: gil on June 12, 2016, 05:26:35 AM
Thanks Ray, that's a great kit for less than $50! Not as small as a Rock-Mite, but frequency-agile..

Gil
Title: Re: Ultra Portable Radios.
Post by: RadioRay on June 12, 2016, 02:03:58 PM
That's my thought: a frequency agile RockMite !
Title: Re: Ultra Portable Radios.
Post by: gil on June 12, 2016, 02:36:19 PM
A frequency agile Rock-Mite with selectable 5-25W power.. Maybe the SW series circuit could be a starting point..

Gil
Title: Re: Ultra Portable Radios.
Post by: gil on June 12, 2016, 02:38:43 PM
And SSB...
Title: Re: Ultra Portable Radios.
Post by: RadioRay on June 12, 2016, 06:10:45 PM
Well, how about single band, 10 Watts CW? Add THIS to the kit:

http://www.qrpkits.com/10wamp.html

I'd love the general coverage receiver, if it would not radically increase the size and power drain.  If so, then the HB1B series looks better.

As for SSB......

(http://www.practicingparents.com/wp-content/uploads/2009/09/smacking.jpg)


you should be a-SHAME-d of yourself!!!

Har-har!

de RadioRay ..._  ._

Title: Re: Ultra Portable Radios.
Post by: gil on June 12, 2016, 06:34:00 PM
LOL, I know, uh, it's not for myself ;-)

I saw that amp.. It would be better to have everything on the same board.. Well, the K2 has a separate SSB board, that is an idea.. It does complicate construction a bit though.

It is true that Morse code is all one needs for emergencies. Nothing more efficient for sure.. PSK31 might come close but it is a 100% duty cycle mode I think and requires a decoder. Not everyone is willing to learn Morse though, their loss.. That is regrettable. I added the SSB requirement because the caller might not be the radio guy, who incidentally could be the victim of the emergency..

Gil

Sent from my A1-830 using Tapatalk

Title: A FUN Reado Re: Ultra Portable Radios.
Post by: RadioRay on June 28, 2016, 08:13:19 PM
Take the term 'operating barefoot' to a new level!

http://www.qsl.net/pa2ohh/bafoot.htm (http://www.qsl.net/pa2ohh/bafoot.htm)


>Ray
Title: Re: Ultra Portable Radios.
Post by: gil on June 29, 2016, 07:02:18 AM
Good link Ray! The author might have sort of a foot fetish, but good story.

Gil