PFR3: Build Complete

I finally finished building the rig about 10 days ago. What an adventure! I last left off having completed Group 2 and started on a group 3. Finishing group 3 was actually pretty straightforward: wind and install a bunch of torroids, and solder in a few more components to complete the transmitter and BLT tuner. The only really tough aspect was winding the monster torroid in the transmitter. Wow--3 interleaving windings, with heavy gauge wire. More on that later...

Recycling an old photo of the board, let me assure you of one thing: random lead clippings that short pins on the programable chip can be quite annoying. I must have re soldered 10 different components before I saw the lead clipping laying there. Assemble, disassemble, reassemble, disassemble... That cost a good 20 minutes. But finally I have the main board complete!

Next, it was time to kit the box. The instructions recommend not kitting until the rig has been fully tested. In retrospect, that makes sense... sigh. Here's how it looks now that it's kitted, though!

The circuit board mounts into the top of the case, with 4 screws which seem to provide ground. That will become important shortly... Kitting everything was pretty straightforward, although I was surprised that the power tap didn't fit. I had to ream out the hole just a bit (nothing a really sharp tempered steel knife couldn't handle). Remember the comment about the external power? Well, if you look really close you'll see I connected the center pin on the external power jack to the ground (white lead), and the outside of the jack to the board's power. Yes, I'm sure you did the math and arrived at the conclusion I overlooked: this causes a short and can really heat up a battery quickly. I'm actually lucky I tested with 8 AA's at 12v rather than a larger 12v SLA battery that could have delivered a bigger punch!

The internal battery pack has sticky tape on it. It needs to be soldered to a wire. This is one of two complaints I have about the entire kit: the plastic battery case melts before the contacts are warm enough for the solder to flow. (My other complaint is about the documentation on T1 and on the monster torroid.) You can barely see it my workaround, but I ended up soldering to the spring inside the battery pack (topmost row, on the far right).

This is the rig, no decals yet. That yellow color is pretty bright--selected to help you find or avoid stepping on the rig while operating in the field.

Connection points. From left to right: power, BNC antenna, switch from BNC to balanced line, and balanced line contacts.

Well at this point I'm pretty happy. My buddy WB6YOK and wrapped up around 10:30 Saturday--another quite long evening and I know my wife will be happy when I'm done disappearing for half a day at a time. I know I will be!

Evidence: it runs on external power. It runs on internal power. It runs!

My preliminary testing was indeterminate--lower power reading on the SWR/power meter, but the antenna was poorly tuned. My Elecraft T1 tuner showed 5+ watts on 40 and 30 (the tuner has LEDs to indicate 1, 5 and 10 watts, so if the rig puts out 4.5 watts it's still not possible to know anything other than the righ puts out more than 1 watt). More testing yet to be done.

Next steps:

1. More output testing: I'd like to buy a few $0.50 50 Ohm resistors, build a dummy load, and test on a matched "line".

2. Install decals

3. Clear coat

4. I'm toying with spraying some reflective clear paint I have on various spots around the rig, to aid discoverability during nighttime

5. I would love to find some small rubber "covers" to put over the 4 switches. The rest of the through holes are actually sealed, but these 4 aren't. We swapped out cable boxes recently, but kept the old remote and it has a few rubber covers which just might work.

6. Build a balanced line and test the BLT

7. QSO! 

I broke this out a couple days ago and tuned around the bands. I was swapping back and forth between my 817 and the PFR. I got a report later from a ham in Oregon that he'd heard me call CQ on 40 but he couldn't get his rig set up in time to answer me (I QSY'ed a bit too quickly). I don't know which radio I was on at the time). 

Between the dummy load and figuring out the "recipe" for my Buddistick, I think I'll have this dialed in shortly.

PFR3 Continues

Just an update: successfully finished group 2, all tests passed (although due to some unplanned massive remodeling at my buddy's, we couldn't get the oscilloscope out). Happy happy! So of course, I soldiered on and started group 3, which begins with a few soldered components and then a pretext. It was on the protest that I completely fell apart. The mistakes?

1. There are two "U8" markings on the board. Pins 1 and 13 are supposed to be at zero volts with the power on and the rig in straight key mode, then 1.2 volts with the key closed. Odd, I was seeing 4 volts on pin 1. Oops... Wrong U8. On the correct U8, I see 0 volts with the key opened and 2 with it closed. The group weighed and said 2 volts is fine--less important the voltage vs. the fact that the circuit is open or closed.

2. Wrong resistors. As I posted to the reflector:

* Manual R6 & R7 should be YEL/VOL/YEL
* Errata: ORG/ORG/YEL
* Installed: YEL/VOL/YEL

Which is right? The errata and the manual agree on 470k, which is YEL/VOL/YEL. Press onward.

3. While troubleshooting the voltage issues, I literally went back to the beginning and checked every single component. Oops, I installed the wrong captor C24. Desoldering, replace, resolder in C56. Oh, whoopsies... Omitted R35 (I remember now I couldn't find it on the board when I was doing stage 2, and apparently I forgot to look again).

Needless to say, I have now checked every component, looked at every solder joint, and made sure everything works. Finally, time to press forward wih L7 to finish the transmitter, so I can start the BLT.

Lessons? Go slow. Mark your questions. Pay very close attention to markings, esp on your caps. If you're tired, stop--rushing won't get it done sooner.

I cannot wait till this is done, if only to put my quirky tom-foolery behind me!

The blue cap on the right side, next to the LCD? Yah, it goes about 5 o'clock from the Dove treat (my wife is the best!). You can see the big trace, right next to the little yellow 104 cap.

See the LCD display? See the conspicuously large resistor spot traced out in white marking, much like a victim's profile at a murder scene? Yah, I don't know how I missed it either!

See the vertical chip just next to the Dove treat? That's U8. Oh, but wait--see the other U8, just below the LCD. Hello, I'm Daryl. This is my brother, Daryl and this is my other brother Daryl. No offense to the boys at Hendricks. I'm sure this is my careless reading of the manual and/or errata. I've made enough dumb mistakes to prove them the experts! And hey, every problem is an opportunity to learn!

Hendricks PFR3 build, groups 1 & 2

If you've read my other blog posts here, you know I'm really interested in light-weight portable operations. That's what led me to buy the Yaesu FT-817, but eventually I realized that was good for park bench or quick day-trip summit work, but it just wouldn't work for a long (3+ days) backcountry hike. 

I reviewed a ton of radios annd came to the conclusion that I needed to learn CW and move to a dedicated QRP rig. After a lot of research, I was about ready to buy an Elecraft KX-1 (http://www.elecraft.com/KX1/KX1.htm). It's highly rated, well-crafted, and quite popular. Then someone turned me onto the Hendricks PFR3 (http://www.qrpkits.com/pfr3.html). The owner of the company was at a QRP meeting listening to someone discuss backcountry QRP operation. An audience member asked what the best rig for backcountry is, and the presenter said it didn't exist yet. He proceeded to list out the features of the dream rig, and Hendricks wrote it all down. He and Steve Weber design, prototyped, and started selling the rig. Not only is it better designed for the backcountry, but it's also much cheaper (the PFR3 currently sells for $240).

About 3 years ago, in 2011, I ordered my kit. I think I sorted the kit the first day I received it, but that's about it. Life got very busy for me, I went through some ups and downs, and now three years later I'm finally building it. In researching the kit, I found there's very little available on the Internet on how to build this rig. If you can't figure it out in the manual, there aren't many resources other than the group. I decided to document the build process so others might benefit.

I am about 4 hours into the build, done with the first two stages.

Basically stage 1 is the LED and power switch. The receiver, stage 2, is most of the right half of the circuit board. The build is very straightforward, except for one item: there's a torrid with a 5-turn primary winding and a 40-turn secondary winding:

I discovered in the course of winding that there is only room for a 40-turn winding, but the manual calls for 40 turns followed by 5 turns. It was all very confusing, until I emailed the PFR3 Yahoo group. A group member clarified: the 5 turns go over the 40 turns. This is probably the least clear portion of the manual.

Another point of conversation: some people have had issues with torroid wires breaking due to the jostling of backcountry travel (shaking in the pack). After discussion with list members, I decided to drop some wax under each torroid. That's what you can see in the shot above. The torroid a are installed on what will be the bottom of the board.

It's difficult to tell, but the radio is powered up and showing 30.0 on the right three digits.

My kit arrived with every component, but unfortunately I lost one of the RF chokes. A list member sent me a replacement. In the lower left of the photo you can see the stock choke--it looks like a fat resistor, just below C42. In the middle of the photo, between the blue and green caps, is the replacement choke. I love the way amateurs help each other out all the time!

Just another random shot of the main board. The kit is very well laid out and goes together quickly--most people estimate 6-8 hours to build. I'm probably 4 hours in, but a lot more considering the head scratching I went through over that torroid!

The manual lists a modification to stage two which address noise in the receiver. It requires two caps to be added--one in a through-hole, and on jumping a couple pins on another component. I was in Seattle on business so I grabbed the components at Frys and installed them with Group 2.

Next step is to dial in the receiver, then build out stage 3 (transceiver). Finally, prep the case and finalize the install.

Backcountry QRP

I've been spending a lot of time researching and preparing to buy a back country QRP rig. I plan on carrying my VX-7R with me on my next 50-miler (coming up in 9 months now), but I really want to have a rig with me that will reach out across longer distances. I want this for two reasons: improved emergency communications and good back country QSOs.

Improved Emergency Communications:
Being responsible for 10, 15 people on a trip is a daunting challenge. I really want to be sure our emergency response plan is solid--that starts with safety, which begins with planning.

• We plan a safe trip, with reasonable hiking distances and reasonable prep hikes. 
• We prepare by ensuring the boys have the skills to hike and camp in the high country of Utah. 
• Our group motto is "Don't be stupid" which really means to not take unnecessary risks. 
• We bring highly skilled leaders--skilled and fit. 
• We focus not just on reaching the goal, but having a good time along the way (hopefully ensuring no one wanders off because they're depressed, lonely, or mad). 
• We bring leaders with a strong first aid background, in case we have to respond to a disaster. 
• Our trip plan has an emergency evacuation plan for each day. 
• On top of that, two years ago we carried a 2m/70cm HT. 

In spite of all this preparation, I was still concerned that I wouldn't be able to reach out for help. Having a leader run back 15 miles to get to a sufficiently high location is one thing - having the trip leader do it, because he's the only licensed operator, is unacceptable. HF isn't a guaranteed QSO, but the options are much better. I can be buried in a drainage, set up a quick 40m NVIS antenna, and send out a signal. That's the hope, at least!


Better Back country QSOs
Let's face it, 2m radio just isn't friendly to the back-country. On these trips, we try to camp at lower elevations which means we're generally down in a drainage, near a lake. Now remember - in the mountains of Utah, 'down' means as low as 10,500 feet above sea level. We're still pretty high! But 2m operation requires line of sight to the nearest repeater, which turns out to be a 2m repeater linked to the Intermountain Intertie system. In order to see it, I have to be at high elevation to clear other mountains. On our last trip, there were about five points (10 miles apart) that met these criteria. With HF, I have a much better chance of sending out a signal--in fact, with an NVIS antenna I have a good chance of hitting people within my general region (Utah). With a standard antenna, well, the continental United States is pretty likely! Bottom line: if I'm carrying radio gear, I'd like to be sure I'm getting out and using it. I want the reward, but I'd also like the boys to get a taste of what's possible.


Operation Mode
So I've been reviewing back country options--obviously I've been into light QRP work, having picked up my 817 last year (and really enjoying the long-distance SSB conversations as far away as Seattle, BC, OH and AK). So of course my initial thoughts leaned toward just hauling my 817 and a big battery with me - and I even have a couple of scouts willing to help carry stuff. But as I added the weight up, I just wasn't sure... For the last long-distance hike, I was carrying about 50 pounds. I started above 65 pounds and come out 15 pounds lighter. And I was feeling it, the entire trip. This trip has to be different...


Meanwhile everyone I spoke with kept telling me the same things I'm reading: pound-for-pound, watt-for-watt nothing beats CW. PSK-31 and other digital modes can really reach out (how about Salt Lake City to Kamchatna on 5 watts?), but PSK means bringing my 817 AND a laptop AND a sound card interface! In the end, everything keeps pointing back to CW... I'm done fighting the trend and I've concluded that I need to learn CW and gain experience operating that mode. And thus, a plan is born...


CW Transceiver Options
Now that I'm going with CW, I have a world of options. Going back to my goals, I want 1) a radio that can communicate in the event of an emergency, without me having to hike to the highest point around, and 2) a radio which can communicate in the evenings when I can have an enjoyable QSO. Moving to CW means there are a number of radios which fit the bill--the challenge is figuring out which radio. Four kits have been highly recommended--I'll try to offer pros and cons of each.

• Elecraft K1: The Elecraft K1 is probably the gold standard for rugged QRP CW rigs. It's relatively small (2.2"H x 5.2"W x 5.6"D), includes an option for internal batteries, and under 1.4 pounds. If you mix and match just right, you can actually get 6 bands out of this tiny rig! Some drawbacks for me, though, are 1) price (nearly $700 with the options I'd want), 2) size (it's a tiny rig but still larger than I want to stuff into my pack), and 3) weight. Add up all the optional components and such and I think you're closer to 2.5 or even 3 lbs. If I didn't own an 817 and I wanted to operate QRP portable CW, I'd probably buy this puppy in a heartbeat. I may yet own one, in fact!
• Small Wonder Labs Rockmite: at the time of writing this, I'm expecting to find one of these under the tree--read my review in a few weeks. The Rockmite is a tiny radio designed for just what I'm talking about: very portable back country use. It's a 40m CW rig that outputs around .5 watts (500 milliwatts--QRPp) on two frequencies. It's ultralight-designed for emergency use. I really can't wait to build mine and start practicing. In fact, my son gave me a Sour Patch Kids tin to put the radio in! Problems are 1) the low output. You always compromise something for weight - in this case, I'm definitely compromising power. 2) dual frequency, single band. This is a purpose-built radio for emergency and probably for 'special interest use' only. NOTE: I am building one, I will use one... I'm not dissing it, I just don't think it'll do what I want.
• Elecraft KX1: I have been looking at the Elecraft KX1 for probably six months now. This is a slick little rig - seriously feature-rich radio packed in a tiny package! It's portable, it can be self-contained (power, tuner, etc.) and can handle up to 4 bands with optional kits. It can output just south of 4 watts with an external 12v battery, too. Normal operating wattage with internal batteries is only about 2 watts though. That's not bad for QRP CW--in fact, even 500 milliwatts can get the job done most of the time. Still, it's got some downsides. First, there's the cost... Fully kitted out (internal tuner, all 4 bands, attached paddles) it'll run close to $600--that's more than I paid for my 817! Second, feedback is that the internal tuner just isn't broad enough to tune everything you might throw at it. Finally, there are additional odds-and-ends to bring with: external power to boost output signal to 4 watts, balun, wire-to-bnc adapter, etc.
• QRPKits PFR3: my final option in this line-up is the QRPKits PFR3. This radio was inspired by the KX1. In fact, it's the build-out of a very experienced answer to "what's the perfect backcountry radio," as answered by Dr. Bob Armstrong (N7XJ). As a long-time owner of a KX1, he had a series of gripes about that radio. As QRPKits' Doug Hendricks listened to Bob present to a meeting of the Arizona ScQRPions club, he took notes. Good notes. And less than a year later, the PFR was born. The best thing about it is the price for performance. For half the cost of the KX1, the PFR delivers two bands (40 and 20), 5 watts, internal manual tuner (with a much wider tuning capability than the KX1), 8 AA batteries rather than six, and a bright yellow case that's just stunningly unique. 

In reviewing this round-up of radios, I've obviously caved and bought myself the Rockmite. That's just because I really want an Altoids tin radio! I've eliminated the K1 for size, weight, and cost. It came down to the KX1 and the PFR3. Frankly, I had eliminated the latter until last Saturday's meeting of the Davis County Amateur Radio club. After the meeting, Bob Cart WR7Q was chatting with me. When I told him I was saving up for a KX1, he referred me to Bob and said I'd love the PFR3. After a LONG thread on the QRP-L reflector, I'm sold - this is the way I'm going.

So I'm saving up, waiting patiently, and anticipating the chance to build out the PFR and report on it. Hope the above really helps - lots of info, but it might save someone else a ton of time researching and saving.

73's

K7JTO