kits – grouchyfarmer

Reviewing the MFJ 8100K World Band SW Receiver Kit

Being stuck in the house “social distancing” (OMG I’m so bored) has some advantages, one of which is being able to get caught up on a lot of stuff. One of those things is the MFJ-8100K world band shortwave radio kit. That’s the little beastie you see in the photo below that I (ahem) ~~stole~~ borrowed from somewhere on the internet.

Damn, that’s pretty slick looking. It beats the heck out of what the average electronics kit looks like when it’s done. Most of them don’t even offer any kind of decent case. Whether it actually will look like this when it’s done remains to be seen because I haven’t actually built it yet as I write this. Instead of putting it together and taking some photos and talking about it after it’s all done, I’m going to do this live, so to speak, writing and photographing as I go along so you too can experience the joys and pains associated with putting something like this together.

I should warn you ahead of time that this could get pretty lengthy because I’ve done little more than just open the box and it is already looking like this is going to be a problem.

But let’s look at the basics a little more closely before we get started. It’s a world band shortwave receiver with 5 bands. They cover 3.5 – 4.3 mHz, 5.85 – 7.4 mHz, 9.5 – 12.00 mHz, 13.2 – 16.4 mHz and 17.5 – 22 mHz.

As for the basic design, this is a regenerative receiver, a design that dates back to, oh, the 1920s or so, and was quickly abandoned as soon as superhets were developed. And for good reason, as anyone who has ever fallen off their chair from the blast of noise if you tweak the regen just a tad too far and it goes into oscillation can tell you. About the only good thing regenerative receivers have going for them is a fairly low parts count and easy assembly. Well, that’s not really true. They can be decent receivers once you get used to their quirks, but with really high quality superheterodyne designs out there, why even bother with one of these? How did I even end up having this on the shelf in the first place? I don’t remember buying it. Do I have people breaking into the house and leaving me stuff instead of stealing it now?

The first thing I started wondering was why the heck is this thing so expensive?It’s going for $90, for heaven’s sake. And there is nothing exotic or hard to find in the electronics. While that variable capacitor is kind of pricey (that goes for about $20+ alone and I know that because I had to buy one of the things a few months ago) But other than that I think there’s maybe $10 worth of parts in the thing. I suspect that really fancy faceplate and heavy duty metal case probably costs more than the electronics inside does.

But let’s get on with this.

Opening the box and poking around.

This is what the promotional photos tells you is in the box.

First I should point out that this kit starting with the photos below is shown exactly as it came and while I assembled it. The box was still sealed and I hadn’t opened it until I started this. What it really looks like when you open the box is this:

Um, okay… Are those screws and nuts rolling around loose in the box? Yeah, they are. And not just screws and nuts and washers, we got electronic components floating around loose in there too. Oh, goodie.

Opening the box and finding components strewn about all over inside doesn’t exactly inspire confidence about the quality of a product. Whoever originally packed this thing and chucked in the little plastic bags holding the components hadn’t bothered to actually close up the plastic bags.

And as for the case, well, damn, that’s probably the best case I’ve ever seen for a kit in a long time. Beautifully finished, heavy steel, with an equally beautiful brushed polished steel faceplate.

You can’t get much better than that. See what I mean about the case probably costing more than the electronics? It’s – it’s shiny. Oooo

The rest of what was in the box looks like this:

The inductors on the right edge were not included in the kit. See text for explanation

As noted, most of the little baggies containing parts were open and had shed a considerable number of electronic components, screws, washers, etc. all over the inside of the box..

Half of “The Wall O’ Parts.” If I need something, it’s probably in there. Somewhere. Maybe. There’s even an emergency backup espresso machine in there

On the far right of the photo above you’ll see a strip of components held together with bits of yellow tape. Those are 3.3 uH inductors and those were not in the kit. I had to dig those out from my “Wall O’ Parts” because the kit wants one, and MFJ either thoughtfully failed to provide one because they figured I’d be getting bored by this time and needed to get up and stretch or something, or it got lost because of they left the baggies open. I expect I shall have to resort to the Wall O’ Parts several times as I try putting this sucker together. I’ve only just started to look at this and sort through parts and I’m already finding stuff missing, so I’m a wee bit irritated. There is nothing more upsetting than getting into an electronics kit and finding parts missing. Me, I have hundreds of components sitting on the shelf (well, if I can find ’em, that is) but the average person building this is not going to have that luxury and is going to be royally ticked off.

The circuit board looks reasonably well made and the parts locations are all nicely detailed. You could probably put it together without instructions if it weren’t for a few gotchas, like having to wind your own coil on a toroid.

Where’s the fecking Manual???

Now, the more sharp eyed amongst you might have noticed something missing from those photos up there. Where the heck is the manual/assembly instructions? Well, you don’t see it because there isn’t one. Instead of a manual there is a half sheet of paper telling me I need to download the manual from the MFJ website, giving me a URL to go to. So I go to the webpage as instructed and find a bad PDF of the circuit diagram which was so low resolution I couldn’t even make out the symbols or component labels. It looked like someone had almost deliberated fuzzed out all of the labels and component symbols, and the “manual” was actually a booklet in PDF telling me how to use the radio, not how to put it together. No assembly instructions. No readable schematic. Oh, goodie…

This ***exactly*** what the schematic I found looks like. Can you read that? Yeah, neither can I

A search on MFJ’s site using its own search function turned up a reference leading straight back to the useless info I’d already seen. I finally ran a general search on Google and found the real assembly manual tucked away somewhere on MFJ’s site and I printed it out.

(Update 3/27/20: And now I can’t even find that website, for pete’s sake! I was going to put the link to the correct PDF in here as I edit this before posting it, and when I just tried I get a “page not found” error. MFJ is apparently upgrading its website and I can’t find it at all. Good job, there, MFJ. I didn’t keep a copy of the PDF, but at least I printed the thing out so I can at least take a stab at this. But anyone else wanting that booklet, well, it looks like you’re on your own.)

The manual itself (if you can find it) is actually pretty good. Sort of. Clearly written, mostly, with lots of detail, but sadly lacking in illustrations.

So let’s sling some solder and see what happens.

Now that’s interesting. Look at the 4 inductors up there. Notice anything different about one of ’em? Yeah, the third from the left is about half the physical size of the other three. The big three were supplied with the kit while the small one is my replacement and is about half the physical size, but it is the right specification according to the color codes and I put it on my tester just to double check, and it should be the right one. Is this going to be an issue? No idea at this point. All of the inductors I have in stock are the smaller size.

Also, more missing parts. Just found two resistors are missing. Look at this pic:

R3 and R6 were missing so I had to pull those off the shelf. Notice that they’re an entirely different color from the kit supplied one, R17. I use the generally more reliable metal film resistors (the blue ones) while the kit supplies carbon resistors (the tan ones). Now very, very rarely the type of resistor can make a difference, so I’m hoping that isn’t the case here.

Later – Missing parts list now sits at 1 missing inductor, 4 missing resistors, and 2 missing capacitors.

And now there’s an issue with one of the electrolytic capacitors.

C14 there next to the IC socket is, according to the instructions, supposed to be a 10 uF cap, but the kit supplies a 1 uF. Or at least I think that’s the one because the 1 uF is the only one left. Do I follow instructions and put in a 10, or use the 1 uF supplied? I finally pulled a 10 uF off the shelf and used that in the hopes that the instructions are right and the parts picker was wrong. (Later – Apparently the 10uF was the right choice because now that it’s done it works)

Watch out for solder bridges or pins with cold solder joints. Here on the bottom row of pins, the third from the left is a bad joint.

And speaking of IC sockets, and this applies to whenever you’re soldering a socket, use caution soldering the pins because it is very easy to apply a tiny bit too much solder and end up with solder bridges shorting out the pins. And it’s easy to do a bad joint as well. Double check under a magnifier.

Time to install the variable cap which is how you tune this puppy. And…

And the solder lugs on the cap are way too big for the holes in the circuit board. I could either drill the holes out, which I don’t want to do because the solder pads are none too large to begin with, or I could trim off the lugs. I finally trimmed the lugs off.

Above here I’m trying to mount the volume control and the regen control. They don’t make this easy either. We’ve gone from holes being to small to holes being way, way too big. Note how some of those holes at the top edge of the board have been double drilled, which makes them way too large for the solder lugs on the potentiometers that are supposed to fit in there.

And speaking of soldering, look closely at those solder pads on that board. It’s difficult to see in the photos but almost all of them seem to be covered with some kind of oxidation that makes it difficult for the solder to adhere. I’ve been using a bit of a scotch brite pad held in a needle nose pliers to buff them before I solder anything.

Then there’s the band switch. The switch has 8 pins, the board has 7 holes. Hmm… Let’s look at the manual. Ah, here we are… Oh, nothing. Says nothing about what to do about the missing hole. Oh, goodie.

I ended up bending the extra pin out of the way and keeping my fingers crossed that it wouldn’t get mad at me. (Later – Don’t know if I was supposed to do this or not but the thing is working this way.)

That circle thing with the white wire wound around it is a coil made by winding 8 turns of wire around a provided toroid core. Some people get a bit weird about winding their own coils. I’m not sure why. A small one like this is a piece of cake. They don’t get nasty until you start having to make ’em with, oh, 30 or 40 turns.

And there it is, ready for testing. It runs off 9V and supposedly a 9V battery will last for weeks and weeks as long as you remember to turn it off. I don’t have a 9V battery, tho, so I hooked it up to my DC power supply and…

Damn, I wish my upload speed wasn’t about 15K baud so I could put up a video of this, but the damned thing actually works! I won’t go through all of the alignment procedures because they will bore you to tears. This is, believe it or not, an actual, working SW receiver. Not a very good one, granted, but it will pick up something.

But then there’s this

This is it fully assembled, mostly. You will note that I don’t have the knobs on. There is a reason for that. MFJ neglected to include the collar nuts you need to actually attach the front properly, anchor the controls down so I can put the knobs on. Now there were indeed collar nuts in the box. You probably saw that in the photos from the box opening. But they were for control shafts about twice the size of these. Sigh… Thanks again, MFJ. Complete assembly is going to have to wait until I can get the right sized nuts.

Okay, this has gone on long enough. Let’s wrap this up. What’s the overall assessment of this beastie?

Well, on the plus side it looks good. It is, amazingly enough, a working radio receiver, although not what I’d call a good working radio. It wasn’t hard to put together. Just about anyone who knows which end of a soldering iron to grab could put this together. Well, mostly, with the application of a bit of common sense. And that case sure looks cool.

Elenco AM/FM superhet kit under construction

But then we come to the negative side.

First problem is the price. They’re getting $90 for this thing, my friends. While the Elenco AM/FM receiver I put together a couple of weeks ago is far more sophisticated, much more sensitive, has an actual amplifier so it can drive a speaker and not just headphones, and sells for half the cost of the MFJ kit at about $44. Granted, it doesn’t come with the fancy case, but you can always cobble together something to throw the Elenco into. And when you’re done with the Elenco you’ll have a radio you can actually listen to, whereas the MFJ is never going to be more than a curiosity for most people.

Then there are the missing parts. A half dozen or so resistors, two capacitors, an inductor, the collar nuts to hold the controls in place, all missing. I don’t know if this was a problem with the person who packed up the parts in the first place, or if they were lost somehow because the bags weren’t closed, or what. My guess is that they were never in there to begin with, because while parts did spill out, the box was sealed and there were no openings for anything to fall out.

As I said before missing parts isn’t much of a problem for me, but for someone who doesn’t have a “Wall O’ Parts”, like some kid doing this for a STEM project or someone who just enjoys occasionally tinkering with kits, this could be a real problem. Sure, you could probably email MFJ and they’d probably replace the parts. Eventually. Maybe. But come on, they should have all been in there in the first place.

Then there’s the manual. Or, rather, the lack of one. What’s the matter with you people over at MFJ? You could throw an 100 page product catalog into the box but you couldn’t be bothered to run off a 30 page manual on the office printer and throw that in too? And then even worse, direct me to a website to find the manual that doesn’t exist? Or to utterly useless schematics?

I’m really disappointed with this because this could have been a really good kit if MFJ had bothered to just just be a little more careful.

So, because of the high price, the missing parts, the missing manual, etc. I can’t score the 8100 very high. On a scale of A to F, where A is excellent and F is abysmal, I’d give the 8100 kit a D+.

Electric Stuff and, Well, Stuff. And the Virus.

When I started moving my stuff from the office upstairs to the new workspace in the basement I knew I was in trouble when I plugged in the laser printer, turned it on, and the lights all went dim. So the electrical contractor got here at 6:50 AM the other morning and some two hours later I had the radio shack/shop rewired with new circuits and outlets. The electrical in this space was a bit scary. I think the whole room was connected to a single 15 amp circuit. I was running my radios and other equipment off heavy duty extension cords running into my woodshop and, well, it was just nasty all the way around. The grand total for all of the work and parts ran about $500 but it’s going to be worth it, for safety alone if not for convenience.

So now I have two, 4 outlet 120V boxes, each on its own circuit, plus a 220V outlet over on the radio bench, and two new 120V circuits for the workbench.

Why call in a contractor instead of doing it myself? Because I know where my areas of competence are. I worked on a farm and in building maintenance for years and I can do just about anything – framing, finish carpentry, drywall, installing doors, plumbing, laying tile… But electrical? I’ve had no training or experience in doing household electrical, and considering how dangerous it can be, well I’m going to let a trained electrician do that.

Tubes & Stuff

So eldest son shot me a text Friday asking me if I wanted a vacuum tube tester, free, and I texted back “r u nuts? yeah i want toob thingie!” or something to that effect and he showed up last weekend with this:

The thing with free equipment is that it’s often going to be something useful only for parts, if that, but in this case it turned out to be a genuine, working vacuum tube tester. Oh, it has a few issues. The tube sockets have some corrosion that needs to be cleaned up and it could use a good cleaning in general. The insulation on the cords is brittle so they need to be replaced, but other than that the thing actually seems to work and inside it actually looks almost new.

on the inside it looks almost brand new.

I haven’t done much with equipment with vacuum tubes of late, but I never know what’s going to show up around here, so this could come in handy.

Tinkering with Stuff

I am building a radio receiver. No, not The Great Radio ~~Fiasco~~ Project. That project is more or less on hold until I can get some parts that seem to have become unobtanium for some reason. I may end up having to change the design. No, this is an Elenco AM/FM receiver kit. Best of all it was free! Well, maybe it was? I found it in a box of junk I was sorting through as I continued the apparently never ending project of cleaning out the basement.

I don’t remember ever buying this thing and have no idea where it came from, but it’s in my basement, in my box, so I’m assuming it’s mine, so I’m going to put the thing together and see what happens. It’s a fairly elaborate little radio and from time to time the instructions seem to go wandering off into fantasy land. I suspect that the instructions that were in the box were written before the circuit board was changed and no one bothered to correct the instructions. So that makes things a bit interesting.

Also in the same box of junk I ran across an unopened multiband shortwave receiver kit distributed by MFJ. I don’t remember ever buying that either, and I would remember since that one costs about $80 and I darn well wouldn’t have spent that much. I suspect both were in a boxes full of “valuable assorted radio parts” (i.e. junk) I picked up for next to nothing at a hamfest, and the box just got shoved on a shelf and forgotten about before I bothered to sort through it.

Weather Stuff

Over the weekend it hit 50 degrees. Almost all the snow melted, motorcycles were out on the streets, a very pleasant weekend all around. Tomorrow it’s supposed to hit 55 degrees!

So, of course, today it snowed. Sigh… I know Wisconsin in known for having some odd weather, but this is ridiculous.

Virus Stuff

I am sure you heard about covid-19. You’d have to have been living in a cave on Mars to not have heard. Wisconsin has only 6 confirmed cases, but the potential of it spreading, and spreading quickly, has everyone concerned. At least one school district has closed, the UW system is extending spring break and advising students not to travel, companies are canceling employee travel. The state basketball tournaments are starting up this week and WIAA just announced that general spectators will not be allowed, only the teams and necessary personnel and a small pool of sports reporters will be permitted.

I want to think a lot of this is hype and paranoia, but, well, I’m right smack dab in the middle of the category of the highest risk for death if I catch this sucker, so yeah, I’m a wee bit paranoid. MrsGF and I are supposed to go to the symphony this weekend, but sitting elbow to elbow in a theater full of hundreds of coughing, sneezing, hacking people for two hours? Uh, no.

What I really find troubling is the huge amount of misinformation being spread, some of it through ignorance, but a lot of it being spread deliberately. Some of it by our own government. I wasn’t going to spend a lot of time talking about this because, well, let’s face it I don’t have that many people who read this so it isn’t going to make a dent in things, but if it helps correct some of the stuff floating around, I suppose I should go into this a bit.

First, there is no cure for covid-19. None. Zip. Zilch. Zero. There is no drug, no “natural remedy”, no combination of herbs, no “silver” concoction. None. If anyone is trying to sell you such a thing, it is an outright scam.

Second, there is no magic herb or substance or “essential oil” or vitamin or magic crystal or “holy oil” that will somehow keep you from catching the virus. Again, if anyone tries to sell you such a thing, it is an outright scam.

Third, there is no vaccine “just around the corner”. Yes, a vaccine is being worked on and there are some promising candidates. But it will be months before one is generally available and even longer before it can be mass produced.

So what can you do?

Wash your hands. A lot. The best preventative is hand washing. Wash your hands using soap and running water. This doesn’t kill the virus, but it does physically remove it from your hands, which is just as good. Do not touch your face except immediately after you’ve washed your hands. A primary method of getting the virus into your system is touching your eyes, nose or mouth.

Do hand sanitizers work? Yes, but only if they’re the right kind. They have to have at least 60% alcohol content. Non alcohol based sanitizers are out there, but no one knows if they actually work or not. The so-called “all natural” hand sanitizers don’t work at all. They’re little more than hand lotion.

Face masks – there is a lot of debate about whether they work or not, and the consensus is that they don’t do much to keep you from getting the virus. They can prevent people who already have it from contaminating others, it seems. The problem, though, is that most of the masks I’ve seen people wearing are dust masks intended to keep dust from getting into your lungs, and were never intended to keep out viruses to begin with. Most people also don’t know how to wear them properly. Heck, I’ve seen a lot of people who have them pulled down to expose the nose. If you do that you might as well not bother at all. Same for guys with beards. If you have a beard, don’t bother. If you can’t seal the mask against bare skin, it isn’t going to work at all.

Social Distancing – what the hell is social distancing? It’s a polite term for keeping the hell away from people. Do not shake hands, do not hug, do not kiss people. Try to keep at least one meter (three feet) away from people if you do have to interact with them.

Avoid crowds. Do not attend sporting events, concerts, meetings or other events where large numbers of people have gathered. I don’t know about where you live, but here most such events have been canceled or postponed anyway. (Although a seriously troubling number have not and are still scheduled). And yes, that goes for church services too. No, being in a church is not going to somehow protect you from getting the virus despite what some utterly irresponsible ministers and priests have been saying. Remember that the primary spreaders of the virus in South Korea when the outbreak first began there were churches. Even the Pope canceled most of his public appearances for heaven’s sake. And if you’ve booked a cruise on a ~~plague ship~~ (ahem, excuse me) cruise ship, well, you’re on your own.

If you’re sick, stay home. About 80% of the people who get it have symptoms that are relatively mild and a lot of people will be tempted to continue with their normal daily routine. And thus risk spreading this to even more people. I realize this is damn near impossible for a lot of people, but the primary way this is spread is by people with relatively mild cases going out in public. Do you really want to be responsible for infecting your friends, your family and your neighbors with this?

Anyway, enough of this. I’ve been babbling long enough.

The Rise and Fall and Rise again of HeathKit and Radio Shack

The story of the rise and fall of companies like HeathKit and Radio Shack is a fascinating and complex subject. I’m going to restrict this to the comeback of both companies. One is almost certainly doomed to failure. The other might manage to hang on and perhaps even succeed.

Let’s look at HeathKit first.

I began getting emails from the company that were a bit, well, odd and, frankly, stupid. Vague announcements that said nothing, press releases that seemed to promise a lot but if you actually read the words, said, well, nothing… They had a web site! Hooray! But there was, well, nothing on it. They kept issuing press releases that promised new kits, upgrades to old kits… Sort of? If you ignored the fact that the tiny, tiny type at the end hinted that, well, maybe not…

Finally, at last, HeathKit is back! Hooray! Yippee!

Yeah, well, don’t get out the champagne just yet, because after all the years of the hype, all of the build up, all of the promises, what we got is this…

Screen Shot 2016 04 04 at 4 06 00 PM

Yeah, that’s it. An AM radio kit. Oh the joy, oh the rapture… Break out my blood pressure pills someone before I faint…

An AM radio kit. For $150.

Note the ultra clean, modern hipster design that eliminates all those unnecessary bells and whistles. Like labels. Or a dial indicator to tell you what frequency it’s tuned to. Or a volume control. Or some kind of indication that the thing is even turned on.

Well to be fair, you don’t need a volume control, I suppose, because it doesn’t have a speaker.

Oh, there’s a speaker for it, or there will be one “real soon now”. A powered amplified speaker. At extra cost, of course. Oh, goodie…

Meanwhile, just plug your headphones into one of the two (Yes, Two! Count them! Two!) headphone jacks.

And all of this can be yours for just $150! Damn, where did I put my blood pressure pills…

Oh, brother… Look, I am going to be brutally honest here. This is just ridiculous. Look, I could literally build this radio out of parts from the junk box in the basement for nothing. Even if I had to buy all of the parts brand new it would cost me less than $30. And for that I’d throw in a speaker and some labels.

But, you say, they must be selling something besides just this, right? Their entire inventory can’t consist of a single radio?

Well, no. Not really. You can get some parts for an old nixie tube clock, a ‘stealth’ VHF antenna that you could build yourself for half the cost, and copies of old HeathKit manuals, and that’s about it. Oh, and little plastic cups for a wind speed indicator.

Now let’s look at the remains of Radio Shack. Yes, it’s still around. While large parts of it were sold off during the bankruptcy, it entered into some kind of partnership with Sprint, and it looks promising.

One of the biggest problems Radio Shack had was it’s entry into the cell phone market. Now the problem when you’re a brick and mortar store that sells cell phones is that people know where you live. In other words, if something goes wrong, they come pounding at your door and demand you fix it. Right now!

This takes up a hell of a lot of time on the part of the sales staff. Which means they can’t take care of people who actually want to buy stuff. Almost every time I’ve been in a Radio Shack store, anywhere, in the past few years, I’ve never been able to actually get someone to take my money.

Seriously. I’d be standing there with whatever little gadget or part I wanted, money in hand, right there at the cash register, and I’d end up giving up in disgust and putting it back and leaving after standing there for ten, twenty, thirty minutes, and all because the staff were trying to activate phones, or trying to explain why your dropping your phone in a toilet is not their problem or whatever.

Needless to say, this business model was not very successful. It’s hard to make money in retail if your staff is too busy with non-paying customers to even ring up a sale.

But Sprint is now taking over the cell phone part of the business, and will have their own staff in the stores. Radio Shack will, I’ve been told, be Radio Shack once more, selling dopey little gadgets, toys, and even actual real electronics parts and tools.

And it may actually be happening because I ran into this…

Yes, it’s a kit. A Radio Shack branded kit. In this case a Theremin, but there were a half dozen more on the rack along with this one. And there were parts. And soldering kits. And multimeters. And breadboards. And power supplies. And, of course, the usual selection of goofy, stupid and sometimes fun little gadgets.

I picked it up for $20 because, well, come on… A theremin? Admit it. You’ve always wanted one.

Now, you can imagine which one of these companies I think has a better chance of successfully resurrecting itself.