Wednesday, April 15, 2020

Midway Electronics ME-80+ Kit

The previous post mentioned Midway Electronics' ME-XX+ kits -- the reincarnation of Dave Benson's mid-1990s SW-XX+ kits -- and how I was looking forward to building them to recapture a misspent youth. Well, as of this writing, I have completed the ME-80+ (80m version) and wanted to offer up some comments and pictures for your perusal.

Firstly, let me say that I ordered the full-blown kit -- board, parts, case, and all the fixins' -- and I do not regret it at all. At first, I thought I would have to replace the 100K Ohm tuning pot with the obligatory 10-turn replacement but the case does not allow it space for it. However, the original pot is of good quality and certainly adequate.

All considred, the Midway guy has done a superb job of offering up a complete radio with some really nice touches.

In addition to the decent case and hardware and knobs, there are some thoughtful "extras" thrown in that make the kit and resultant radio a "keeper". Thoughtfully provided are the header strips and cabling to give the radio that finished look. Also, the snap-in standoffs are pretty easy to install. Although I went with my own standoffs, the ability to extract the board from the case by unfastening the cables and lifting it out makes for easy debugging and repair. I would only add that Dave's original kits did not have an on/off switch and the Midway kits don;t either; it was something I always lamented. (As you can see from the pictures below, I added a a switch.)

Diving into the kit is a lot of fun. While, conceptually, it's straight forward to build and the manual is nearly identical to Dave Benson's SWL manuals, it is not part-by-part but rather block by block. (Or, if you will, quadrant by quadrant; see sample below.)


My philosophy regarding kit building is like my old adage: "I burn up more rolls of solder than I do log books." I take it slowly and enjoy it. I mean, after all, it's not like I don't have any radios to operate. At a decent, leisurely pace, it took me four days to build the kit working two hours per night.

The board is superb! In fact, it is better than Dave's boards as I recall. But I would caution you that, if you are not an experienced kit builder, you'd best inventory the parts and organize them so you gain some familiarity. There is nothing worse than stuffing a 47 Ohm resistor into the holes for a 47K Ohm resistor's holes and have to dig out the mistake during the checkout process. Also, read and understand the freaking manual first. There are some tips and caveats in there that add to the fun of getting the build right.

Once assembled, the checkout is very simple and -- quite literally -- can be accomplished with a DMM and your station rig. For example, at power-up, I heard nothing on both receive or transmit and resorted to the voltage schematic provided. I discovered no Vcc present at the two receive SA612 ICs and scattered places around the board. When I examined the traces from the 78L08 voltage regulator output to these ICs I noted that I had installed D2 (a 1N4148 diode) "upside down" and it was a roadblock to the DC rails. This little tidbit was addressed in the manual:


Correcting this (flipping the diode) cleared up 99.99% of the problems.

This next point was not really an error on my part. Dave's design uses three of the old Toko IF transformer cans -- two in the transmitter and one on the receiver. Aligning the radio is a simple matter of tweaking the cans to obtain a peak signal out (transmitter) or a peak signal in (receiver). The transmitter was no problem and I was able to peak the radio at 2.5 watts. (Despite the advisory to throttle the rig back to 1.5 watts, I felt comfortable at having it output 2 watts.)

But, when I attempted to peak the receiver, it was number than a rock. In adjusting the receiver transformer, I noticed that the slug in the can neither moved up nor down and reasoned that the threads had been stripped. The best it could hear was about -70 dB. So, since I had a couple of those Toko transformers on hand (marked "412F123"), I opted to wick out the old one and replace it. This was a tricky job but, once accomplished, the little receiver heard all the way down to an honest -130 dB!

My recommendation is that, when you inventory the parts, check out each transformer by carefully screwing the slug in and out to make sure it travels up and down. If one does not, ask Midway for a replacement. Also, please note that I do NOT lay this at Midway's feet. Their conscientiousness and customer service and kit quality is stupendous! One just slipped through!

The final step is to set the frequency by inserting in an NP0 cap into C7 for the desired range. As it turned out, mine required a 56 pF cap (that actually measured 60 pF) which gave the little radio a range of 3.499-3.537 MHz.

I can live with that! Anyway, here are some pictures:










This is a fun kit that results in a serious radio that has been proven over the years and is a great starter kit for those who have graduated from the Chinese Pixies and want to get their hands on something with a little meat on its bones.

..now on to the ME30+ kit!

Tuesday, March 31, 2020

Living in the past - Dave Benson's SW+ radios reincarnated!

Back in my early days of QRP -- mid 90s to be approximate -- I fell in love with building kits as a byproduct of this black art. My first was the marvelous OHR-100 One which convinced me that low-power contacts to Northern California (I live in SoCal) were do-able on five watts.

This was followed by one of Dave Benson's SW+ series -- an SW-30+ for 30 meters -- that was started on a Friday evening and concluded with an alignment session on a rainy Sunday evening. After strapping it to an old 4BTV vertical leaning against my patio wall (the only option available), I pumped 1.5 watts out to the ionosphere and landed WB0CFF in Minnesota. The memory of that QSO still makes my hair stand on end even though I have worked considerable DX since then.

That said and in a possible effort to re-live past triumphs, I ordered a Midway Electronics ME-30+ kit -- the "board only" option -- as a means to "fill in the gap" between my old SW-40+ and SW-20+ builds that grace the shelves. For the curious, I thought I'd pass along a few comments and impressions.

It seems that Dave Benson granted the proprietor license to exactly reproduce and distribute his popular SW+ 2-watt kits, arguably part of QRP's heritage and as significant as the NorCal 40A and similar.

The kit was received in short order but, sadly, it was the 80m kit. (80 meters is dogmeat in Southern California and in my neighborhood specifically.) However, email conversations with the owner resulted in him sending along the 30m components with an advisory to keep the 80m components. I was flummoxed with the initial speed of delivery, the follow-up correction, and the overall friendliness and attitude of Midway with respect to customer service. (To be sure, I planned to return the 80m part but read on.)




The kit(s) -- boards, parts, manuals -- are, as stated, an exact replica of Dave's original product. Moreover, the prices are very similar to the very reasonable prices that Dave used to charge: $60 (versus $55) for the board kit, $92.50 for the board kit and controls and project box (versus $95). Given that the Toko coils and 8-pin DIP NE602s are rare, I find this astounding. The quality of the PCB is extremely good and it is identical to Dave's. The manual comes spiral bound and as easily understandable as Dave's was.

I was so wrought with guilt over being told to keep the 80m parts that I requested he send me the makings for both radios to be "full" kits. That's an additional board, front and back panel components and knobs, and two cases; a very reasonable price was quoted and they are on their way. The subsequent order was delivered and the quality of the cases are quite good. The only niggling downside is they fit the board and controls and connectors exactly leaving little room to stuff additional items like a keyer chip board and frequency enunciator. But that's not Midway's problem, that's my problem.

The kits, components, cases, etc. are available in 80m, 40m, 30m, and 20m editions on Midway's website:

https://midwayelectronics.us/qrp/

They are also available on eBay. Search for ME40+, ME30+, or ME20+ -- and presumably the ME80+ will be available there soon.

In summary, I am very happy this gentleman has chosen to bring back this kit. It provides us old codgers a chance to relive our past. For those "new" to QRP an opportunity, it's a opportunity to develop their understanding of radio and electronics as "Elmer 101" courses and in depth discussions abound for this radio.

When I get this kit built, I will post pictures and notes for those interested.

Usual disclaimer: no pecuniary interest, etc.

Wednesday, January 22, 2020

Zuni WFD Get-Together Venue Change!

Mike, N6MST, just saved our bacon. All the way up in Bakersfield, he spied that Mile Square Park -- where we were originally to meet - was going to be occupied the entire wekend by the Vietnamese New Year -- Tet - celebration so, consequently, we are moving the venue a little down from there.

My so-called Plan "B" has become Plan "A" and it involves our commandeering a part of the green belt in my community. There are trees and a vast open space and, with our bringing two or three portable tables and chairs, we can set up there. See the pictures below. The Green Valley Park offers these advantages:

(1) Some trees.
(2) Open spaces where verticals and poles for antennas can be erected.
(3) Abundance of free parking that is walking-close to where we would set up.
(4) No crowds to speak of.
(5) Restaurants/7Elevens close by. CostCo also close. ($1.50 dog and a coke special ant their "food court".)
(6) Close to my QTH so we can grab some stuff from my shack/bench if we need to.

Some downside: we are going to need for folks to bring chairs and another table. I have a table and two chairs but it's not conducive to operating or outgassing if everyone does not have a chair.

So, we will still coordinate on the PAPA System so give us a call there if you are lost.

Sorry for the change but this should still be tons of fun and we're still doing the pizza debrief afterwards.

To get here, head South on the 405  to the Brookhurst Street and go under the freeway and loop around so you're heading North on Brookhurst. turn right on Warner and proceed past Ward (the next light) to Los Jardines wher you take a right. we'll be listening on PAPA or 146.52 MHz to talk you in.








Monday, January 13, 2020

Get a grip..

In an attempt to scrape some rust off my CW fist, I am currently matriculating through the CW OPs CW Academy and it is a marvelous experience. Sure it's the beginner class and sure I can solid copy around 15 WPM but I am doing this for the discipline -- and getting myself into a routine of practicing my CW daily.

But more on that later. The purpose of this post is to bring CW operators attention to a discovery I made -- thanks to my wife. She found this stuff called Grip Liner Magic Cover which is billed as a non-adhesive and non-slip cupboard liner for dishes and glassware. It is by Kittrich Corp in Pomona, California and can be found in many homewares stores, super markets, and it and variants are available on Amazon. (You do your own search.)

A small square of this stuff anchors my paddles to the desktop and essentially squelches any side-to-side slipping. So far, the squares I have been using for my Bencher (below) and Kent (out on the shack) are well over six months old. So, a roll of this stuff should last a lifetime -- and more.



Wednesday, January 8, 2020

It Begins! Prepping for Zuni Loop MEF Field Day 2020!

Rust Never Sleeps!
The Zuni Loop Mountain Expeditionary Force is an ad hoc association of some of the best and brightest QRP ops who came together each year for ARRL Field Day. One of the groups consistent mainstays and organizer for the past 35 years was Cam Hartford, N6GA, who ensured that QRP and antenna and operation experimentation resulted in good contest results, an enhancement of participant knowledge, operating skills, and -- mainly -- fun!

Sadly, Cam left us last year before Field Day and we carried on as best we could. But, armed with that rebuilding experience and a determination to regain past glory, we are resolved to not let the tradition of Zuni Loop fade away. What we have going for us is this tradition and one heck of a great location. But we will peak of that later on. For now, the planning begins.

Where We Sit Now
We need more ops. So far we have a commitment from three veterans and four promising new-comers: John, n6vcw (trustee of Cam's N6GA callsign - now officially assigned to the Zuni Loop MEF), Ed, KM6TNT, Matt, KM6TOA, and Mike, N6MST. The returning regulars include Dick, WB6JDH, myself, K6WHP, and long-time Zuni veteran, Keith Clark, W6SIY. Ed has done a great job in recruiting and has secured three new hams to join us for 2020. We welcome them and others with a profound interest in QRP and pushing the envelope. If you are intrigued and proximate to Southern California, let us know. My email is good in QRZ under my call sign or click on this link and blast away!

Preparation and Related Logisics
Our first step in preparing for Field Day will be participation in the Winter Field Day on 25-26 January. We will be setting up in Orange County at Mile Square Park in Fountain Valley.


While Winter Field Day is a contest and we will set up to operate -- patterned after the Summer Field Day but with a few rule changes -- our emphasis will be a little different. Our main goals will be to get to know one another, check out some equipment and antennas, orient folks not familiar to in-the-field QRP operation, and generally observe the newly coined variant of the Zuni Loop motto:

We're deadly serious about having fun!

Although Winter Field Day goes overnight (like Field Day) for two days, we will only set up and operate for a short time, from about 0900L PST until about 1500L PST. Note that the actual contesting starts -- like FD -- at 1100L but we want to get a head start with prep and such. Also, I live adjacent to the park and will be heading over early to stake out tables and trees at an appropriate site. (Probably will be "spot #2" per the map below.) If you wish to coordinate the entry and "carpool" into the park, there is parking in the adjacent strip mall next to my QTH. I would recommend coordinating with Ed, KM6TNT, on this noting that we both can be found on the PAPA system. It is one of those sprawling, linked "closed but welcoming" repeater system whose info can be found at this link here. Suggest PAPA 03 or PAPA 04 as you penetrate Orange County.


Mile Square Park park charges $5 admission on Saturdays and does not allow re-entry (unless you pony up again), so I recommend picking up something -- sammiches, sodas, etc. -- for lunch around noon time if only to stave off hunger. We will probably have donuts and/or bagels available at first but if you you are a coffee drinker, you are on notice that I am not and your daily caffeine hit is your responsibility. 

We plan on folding our tents and heading over to a pizza joint close by where we can eat, "hydrate ourselves", and debrief. This socializing will be an invaluable opportunity to gather our thoughts and ideas in preparation for the real thing.

Prerequisites and Skills Required
Again, if it looks like you want to participate in the Zuni Loop MEF effort this is a great way to get to know the folks. If your CW is rusty or non-existent, don't worry! we do phone too and you will be surprised how -- with a little coaching -- you can pick up CW contesting by logging and using a CW reader. Also, don't let low power throw you. Up at 7,000 feet, a five watt signal carries pretty far. Several of us have done WAS (Worked All States) during a field day. (I have done it three times and once I came within four states of doing a "double WAS".) Also, foreign countries now participate in Field Day so there's a chance for DX as well.

Send me an email and I'll answer any questions you might have.

Park Environment
For reference and orientation, here's some pictures of the Mile Square Park surrounds.

K6WHP QTH, External Parking, and Mile Square Park Spots

Map of Mile Square Park


Friday, December 20, 2019

Simply Half-Wave Trapped Antennas Addendum 1 - Nice to Have Stuff

Paul Carlson in a small part of his lab
This is a short rant about [electronic] tools and what you should anticipate arming yourself with.

If you are new to ham radio and foresee getting into serious tinkering, First get yourself a DMM (Digital Multimeter).

Period.

These range from literally free (with a coupon from Harbor Freight Tools) to a Fluke (or higher grade instrument) that will cost you almost a thousand buckos. Scout YouTube for some reviews but cease once your eyes begin to glass over. Guys like Dave, the histrionic Aussie host of the EEVBLOG series, will have you believing you cannot survive without owning a Fluke meter that can withstand being thrown off a skyscraper. M. J. Lortin, the laconic Englishman, will have you sound asleep five minutes into part one of an hour long video of which there are two additional parts.

Other guys will show you anywhere from three to ten DMMs they bought just so they can do a review of the infinitesimally subtle differences between each. Trust me, if you get a decent one for about $15-50 with auto-ranging and a few other features you might want, you will be fine. Also, trust me: it will not be the last one you own.

O.K., that covers DMMs and we'll leave oscilloscopes for later. But, when you get one, you will be surprised how you did without it.

I would only add -- for the moment -- that you make a modest investment into three items that will save you a lot of headaches, guesswork, and make this corner of antenna and radio building a lot of fun. These are a component checker, an LC meter, and an antenna analyzer. Examples of these are shown below but are not exact product recommendations. They are part of the bounty of cheap Chinese stuff exported and sold on eBay for a reasonable price. Recommendations can be sought amongst friends and on VHF/UHF technical nets and round tables. Wise shopping will set you back from $20-100 tops.


Component checkers are surprisingly good at telling you a lot about each little doodad you hoover up at swap meets from transistors to inductors and including resistors, capacitors, diodes, and other stuff. They might even be good enough to tell you about the inductors and capacitors you are using for your traps. They are around $15-25 on eBay.
LC meters are higher quality gadgets that give you a more accurate reading of the inductors and capacitors. If your component checker is crappy, then consider one of these. They are a little more than $20 on eBay.
Antenna analyzers range from cheap to literally a kilobuck (or more). If you pick up one for HF only (1-60 MHz), expect to pay around $50-80 for a low end one. I have a couple I picked up in that price range and am perfectly content with what they show me and don't need curves of graphs drawn.
But, trust me, you start tinkering and you will always see "something better" and end up having about three or four items that essentially do the same thing. Of late, there is a "NanoVNA" on eBay that sells for about $60 and will actually draw curves of your "network" (the trap). If it is sexy enough to compel you to open your wallet, knock yourself out.

If you want to go old school, you might consider picking up something called a Grid Dip Meter or "GDO" (Grid Dip Oscillator). Back in the day (the 1950s onward), these were considered the "Swiss Army Knife" of test instruments as they could be used to test LC tank circuits, antenna resonance, and even serve as a signal generator. Here, Alan Wolke, W2AEW, does a nice video on how these can be used.


When my dad passed away back in 1992, I inherited his Millen 90651A which, at the time, was considered the Cadillac of GDOs. I developed a "jones" for these and over the course of time owned a number. The collection dwindled but I kept my dad's and the cream of the crop and still use them quite a bit, to wit:


The Heathkit transistorized version of this -- like the one in Alan's video -- is worthwhile and is as near as good as the Millen. The Millens and the Heathkits are not worth owning if they are in questionable condition or do not have the coils with them. Most of the time, the ones offered on eBay are dog meat and way overpriced at that. Occasionally, one will come along and is worth nabbing. Even better is picking up one at a swap meet or ham fest.

Alan produces some outstanding technical videos and they are well worth watching. His work is thorough, explanations are straightforward, and he publishes those magnificent notes he makes for download from a link on each video.

Another simple "old-school" tool is the noise bridge. These are simple circuits that generate white noise. As explained by an Australian, Ralph Klimek in a 1995 article on his website:
A noise bridge is an impedance measuring device that can measure real and imaginary components of complex impedance at RF frequencies. It uses a radio receiver as a detection device and a broadband noise source as the excitation source for the bridge. This eliminates the need for a precision signal generator notwithstanding the fact that the average signal generator does not have sufficient output amplitude to excite and bridge and simple detector. A radio receiver is an excellent detector being sensitive down to microvolt signals and low bandwidth. The noise bridge is an excellent antenna tuning instrument because it gives a rapid and precision measurement and also the noise power induced into the antenna is very small and will not cause interference to others.

Basically, is is an even cheaper version of an antenna analyzer and, if mastered, can be quite useful.
There are "commercial" products available like the venerable Palomar Engineers version or an old Heathkit, and an MFJ unit that turn up from time to time on eBay priced from around $20 on up. I would not, however, pay more than $40 for one. These are shown below:


There is a kit available from QRPGuys for about $20 plus shipping. It works identically to the units above but the advantage is that you get the experience of building it and there is a comprehensive assembly manual here and an "operations manual" here.


Like the GDO above, if you see a noise bridge at a swap meet or ham fest for a reasonable price, pick it up and learn to use it. Anyone can drive one of those idiot-proof antenna analyzers but it takes going old-school to really understand the underlying electronics and antenna theory.

By the way, Paul Carlson is one of the more impressive techs on YouTube. His lab (a smidge of which is shown in the picture above) is truly expansive and, given that he is prone to radios and equipment built in the 50s and 60s, borders on the Gothic. Don't let this put you off. The man is a genius -- both in the literal sense and as a statement of my admiration for him. His YouTube channel is a treasure trove. Here is the intro.

Simply Half-Wave Trapped Antennas Part 4 - Putting the Antenna Together

A small contingent of the The Zuni MEF will be doing Winter FD but not as a contest, rather a one day antenna and rig "burn in".


As part of that, I will be assembling both a 40m/20m trap dipole as well as a 40m/20m trap vertical and will have pictures and notes on that in this space.

..see you at the end of January 2020.