Building a Weber MTR.

Started by gil, March 23, 2013, 11:10:20 PM

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gil

How much can you fit in an Altoids tin? Not much, as far as radios are concerned. There is of course the proverbial Rock-Mite, a single-frequency crystal driven transceiver we all have learned to love. But times are changing, and surface-mount components are replacing through-hole ones, giving us really tiny devices. It probably won't be long before I can't even see the darn things. Soldering them isn't that hard mind you, just very precise work with a good magnifying lens and a fine-tip iron.

Enter Steve Weber KD1JV with his A.T. Sprint series. The latest of his realeases is the MTR, or "Mountain Top Radio," a two-bander with full coverage, digital VFO, message memories, built-in keyer, one-digit display and Morse frequency feedback. Amazingly it does fit in an Altoids box! Not only that, but power output is a hefty 5W! Talk about QRO! It will even work down to 5.5V (12V max). It also does PSK31, with a computer. Unbelievable!

These kits are only available to members of the AT Sprint Yahoo Group: http://groups.yahoo.com/group/AT_Sprint/. They are rarely available. 150 kits were made and 149 offered on Thursday, early morning. I believe they were sold out by noon! Quite a few people who did not check their email early enough missed it. They were gone within hours. At only $120, that isn't surprising. The kit would sell for twice that price. So, my hat is off to Mr. Weber.

Guess who got one?

Hehehe, I'm still giggling... Order #124, yep, barely made it. I should get it some time this week.

I will post my building process with photos.

I am planning a one-week QRP camping trip soon, and the MTR will ride along, with my trusty PAR End-Fed. I bought an ICS (Improved Combat Shelter) one-man tent made by ORC Industries for the military. I will also be testing a newly acquired Thermarest pad and a couple other pieces of camping gear. The MTR will be powered by eight AA cells, which I hope to recharge with a flexible solar panel. I will probably have one radio session on 20m in the morning, and one at night on 40m, CW of course!

Stay tuned for more  :D

Gil.

Geek

I'm not only interested in the radio, but also the solar charging and the tent.  Links or pictures would also be appreciated.

cockpitbob


gil

All right then... On top of this MTR build thread, I will post a "Radio Camping" thread on the tactical board. It will include all the gear I will be using, including tent, backpack, stove, solar panel, batteries, QRP rig (MTR), Antenna (End Fed), and whatever else I find relevant to operating in the boonies. I just ordered a BetterQRP (http://betterqrp.com) End-Fed-Half-Wave tuner and will try to duplicate my PAR End-Fed, which is semi-permanently installed at my house. I am also building an 80m end-fed matching box, but I will probably not take my KX3 with me, so that will be another thread. I will most likely mount my American Morse DCP paddle on the MTR enclosure.

The MTR should arrive tomorrow or Friday. I will probably post videos as well.

Gil.

Geek


gil

#5
The MTR arrived today! Man, that thing is small... The case, made by TenTec looks great, though a bit thicker than an Altoids box. I was going to sell it and use an Altoids, but changed my mind and will use it. I could step on it with no ill effect.

I started the build using my soldering station and a fine tip. The resistors went on first, then the capacitors. It took me exactly four hours to install them all. It is actually faster and somewhat easier than through-hole components, except for the size. A good magnifying lens is a must. When I say "a must," I mean that you can't build without one. Also a plus is the fact that you don't end-up with a bunch of component leads on the floor.. One thing you absolutely need is a steady hand, otherwise, forget it..

I plan on one or two more sessions to finish it, by Monday, I am sure. Have a look at the attached photo.. The PCB (sorry, it's upside-down) shows the bottom side, with all resistors and capacitors installed (yes, there are many components on that board, look closely!) The coin is a penny. The tiny black dot below the coin is a resistor!

Those chips are going to be a real challenge to solder..

TGIF!

Gil.

Geek

Quote from: gil on March 29, 2013, 02:01:27 AM
The MTR arrived today! Man, that thing is small... The case, made by TenTec looks great, though a bit thicker than an Altoids box. I was going to sell it and use an Altoids, but changed my mind and will use it. I could step on it with no ill effect.

I started the build using my soldering station and a fine tip. The resistors went on first, then the capacitors. It took me exactly four hours to install them all. It is actually faster and somewhat easier than through-hole components, except for the size. A good magnifying lens is a must. When I say "a must," I mean that you can't build without one. Also a plus is the fact that you don't end-up with a bunch of component leads on the floor.. One thing you absolutely need is a steady hand, otherwise, forget it..

I plan on one or two more sessions to finish it, by Monday, I am sure. Have a look at the attached photo.. The PCB (sorry, it's upside-down) shows the bottom side, with all resistors and capacitors installed (yes, there are many components on that board, look closely!) The coin is a penny. The tiny black dot below the coin is a resistor!

Those chips are going to be a real challenge to solder..

TGIF!

Gil.

Are you trying to talk us out of this end of the hobby?  :-)

gil

#7
Of course I want everyone to get into QRP CW! Hehe... Every ounce counts when you are on foot. Look at extreme hikers.. Some even cut their toothbrush in half to save weight. In a "teotwawki" situation, we would soon all be on foot..

Gil.

cockpitbob

I highly recommend a magnifying visor.  Here's the one I use with the 4X lens that comes with it.  this is much better than a magnifyer or even a microscope.  You get sterio vision and you can move your head instead of having to more the work.  I work with surface mount parts all the time and if I don't drink too much coffee I'm comfortable with the 0603 resistors (0.06" x 0.03") using the visor.

And, after your 45th birthday you'll find lots of other uses for the magnifyer  >:( .

gil

I thought about getting one...

RadioRay

#10
Your MTR signal sounded good!  Amazing to span over 800 miles in an easy conversation about camping and etc. using a transceiver that can easily get lost in your pocket.  ha ha


de RadioRay ..._ ._
"When we cannot do the good we would, we must be ready to do the good we can."  ~ Matthew Henry

gil

Thanks again Ray for your help. If only my paddle didn't decide to misbehave.. Must be dirty contacts as you suggested..

The MTR is alive! I will post photos and a video soon. Soldering some chips was a real challenge. I didn't think it would actually work the first time out. One segment of the LED display was out, I had forgotten to solder that pad. I do have only half power on 40m, and need to troubleshoot it. The receiver is pretty sensitive, the sidetone sounds good and the 500Hz filter works great.

Did you say S7 Ray? That's pretty good 800+ miles away.. Well, 3W is 3W.. I would probably get about 4.5W at 12V. I used seven AA batteries. I have a 13.8V power supply at home, and might put three diodes in series to get 12V (3x0.6V drop). For the field, I have eight-AA battery holders and 1.2V cells. My solar panel should arrive this coming week.

I can't help but compare the MTR to the PAR Mantiz. Both great radios. Of course the Mantiz is available, while the MTR rarely is. Band choices can be debated all day. The MTR covers two bands out of 40, 30, 20, and possibly 80m. The Mantiz is 30/40m. Tunnig is of course easier with the Mantiz which uses an encoder and has an LCD display. The MTR uses switches and has a one-digit display. Either way, it works. Better than I thought on the MTR. Power is similar. The Mantiz has variable filters while the MTR has a fixed 500Hz filter. The Mantiz filters however can't be centered precisely. The MTR also does not have a SWR meter like the Mantiz. Both rigs have a memory keyer. The MTR is definitely smaller; it also draws slightly less current. The main difference between my Mantiz (sold it) and the MTR is that I actually built the MTR! There is a certain emotional attachment here.

I recently read "Three Hundred Zeroes" by Dennis R. Blanchard, who actually carried an A.T. Sprint (Steve Weber design) CW QRP rig with him on the Appalachian trail. He did meet Steve Weber on the trail.. Turns out, the author lives in my town! We exchanged a couple emails and might meet some time after a big European bicycle trip he is preparing for.. What are the odds!? Anyway, my point is that for trail hikers, weight is an obsession. Every ounce saved it seems does count. That is when having a small CW QRP radio does pay off handsomely. A lot of remote areas of the United States, not to mention the rest of the world, do not have cell phone coverage. The maximum pack weight suggested is 20% of body weight. For me, that means about 38Lbs max. That isn't much. Imagine carrying a 10AH SLA battery, maybe a KX3 or FT-817ND, plus antenna.. That's a big chunk of your allocated weight there.. Of course people will say "I'll never have to carry a heavy backpack because blah, blah blah.." How do you know? Hope for the best, prepare for the worst.

Gil.

gil

#12
Well, even though I am still only putting out 1.2W on 40m, I hust has a 5200 miles QSO to Estonia with the MTR! Antenna is the PAR (LNR) End Fed.

Gil.

Geek

Estonia!  Cool!  Now you know where you can check in to find out if the Zombie apocalypse is worldwide!.  LOL

gil

#14
QuoteEstonia!  Cool!  Now you know where you can check in to find out if the Zombie apocalypse is worldwide!.  LOL

You're never too careful  :o

I fixed it! I wrongly swapped two capacitors because of some confusion in the old (a new one was was published) building manual. Now, with a 10V supply, I get 4W on 40m and 3W on 20m. Still a bit low on 20m, but if I use a 12V supply, I should get decent power. I am glad it was something simple, because those capacitors have no markings on them. If you don't know where to look, it can be a nightmare; as in unsoldering them all! Which for SMT components is not easy. I decided to try it on the air right away and called the first guy I heard, in Germany! I got a 449 report. Not bad for a 5000 miles QSO on 4W!

I love the MTR! For a trail radio, there is nothing better. It weighs almost nothing, even with the steel case. It's a keeper for sure.

There is something special about using a radio you built yourself, especially if it was difficult. The MTR is definitely not a beginner's kit. It took less time but was harder to build than my K2. It is also amazing to talk to someone 5000 miles away with a radio that fits in a shirt pocket or an Altoids box! How crazy is that? And not just by chance, regularly!

Ya'll have a great day  ;D

Gil.