James reviews the Heathkit Explorer Jr. GR-150 TRF AM radio receiver kit

HeathkitExplorerJrMany thanks to SWLing Post contributor, James Surprenant (AB1DQ), who shares this review and photos of the new Heathkit Explorer Jr. TRF AM radio receiver kit:


 Heathkit Explorer Jr. Review

I received this Heathkit kit for Xmas from dear old Dad.

Heathkit Explorer Jr. Manual

The Explorer Jr. manual is very nicely done, spiral-bound, and very reminiscent of the old Heathkit manuals in terms of lay-out and detail.

Heathkit Explorer Jr. Retro envelope packaging

The packaging of the parts is also reminiscent of the old Heathkits with parts grouped into envelopes by phase, ie. “Active Components,” “Passive Components,” “Small Parts,” “Knobs,” etc.

The first night, I worked through completion of the circuit board attaching all electronic components and stopped at the step for winding the coil. I thought it would make sense to start fresh on that step since winding coils is generally a pain.

Even on the first night, I had a few criticisms:

  • A couple of the envelopes were ripped open when I unpacked the kit. There were nuts, bolts, spacers and an Allen wrench loose in the outer box. That said, no parts were missing.
  • I found two errors in the manual:
    1. The color code for one of the resistors was incorrect in the manual. With my aging eyes, and the miniaturization of components today, I always use an ohm meter to test all resistors before attaching them to the PCB when I build a kit.

      Incorrect color code in manual.

      Incorrect color code in manual.

    2. The circuit contains 10 resistors and all 10 were included in the kit. But one was completely missing from the step-by-step instructions. After I finished attaching all active and passive components, I had one resistor left over and fortunately there was a matching empty space on the circuit board for the same value resistor. I double and triple checked the instruction manual and I can not find where it calls for this resistor to be attached.
  • My biggest criticism so far is the fact that this kit is “solder-less.” All components are attached to the PCB with screws, lock washers and a nut. You insert the leads for each component through the over-size pass-through holes on the PCB, and bend the leads tight against the edge. Then you insert a screw in from the topside, place a lock washer on the bottom side and fasten with a bolt.
Bottom of the PCB board

Bottom of the PCB board

On the upside, the fact I didn’t need to work with a hot solder iron meant I felt comfortable building the kit at the kitchen table. (My XYL would not be pleased if she found burn marks on the table!) So I had a nicer environment to work in than the basement work bench.

Heathkit Explorer Jr. sheered off resistor leadsOn the downside, I managed to sheer off the leads on TWO resistors when tightening the screws. Fortunately I was able to replace the busted resistors from my on-hand stock.

The other odd thing about this method of attaching components is that Heathkit included a nifty screwdriver in the kit, but leaves it up to the kit builder to provide a small socket wrench or pliers to hold the nut in place while tightening the screw.

Finally, the instructions call for the kit builder to ‘bend the excess leads back and forth’ until they snap off, rather than instructing the kit builder to snip off the excess leads with nippers. That seemed really strange to me.

Heathkit Explorer Jr. Completed coil

I completed my build of the GR-150 Explorer TRF radio this past weekend. I had no difficulty winding the coil, which involved 56 turns of magnet wire around a ferite core and securing it with transparent tape.

Heathkit provided the black ties, which were too large.

Heathkit provided the black ties, which were too large.

The next problem I encountered was attaching the wound coil to the PCB. The kit came with two zip cords to use as fasteners, but the zip cords were much much too large to fit through the holes drilled in the PCB. So this required a trip to the hardware store.

You can clearly see that the holes are too small for the black cable ties.

You can clearly see that the holes are too small for the black cable ties.

Once I had the coil mounted, I encountered the problem again with the bolts and nuts shearing off the leads – this time, it took me about 4 tries to attach the thin fragile coil wires to the PCB. It’s a very fragile process that again had me wishing this was a solder kit.

Heathkit Explorer Jr. Top of PCB front

The rest of the assembly went well. The only other glitch I encountered was in assembling the cabinet, the kit came with six locking star washers for the cabinet, in fact the parts list indicates that six should have been included in the kit. But then the actual assembly called for 10 star washers.

Heathkit Explorer Jr. Top of PCB

Heathkit Explorer Jr. Nearly finished frontHeathkit Explorer Jr. Completed PCB mounted

So, how did the radio perform? About as expected. It is a single stage TRF receiver without a proper audio amplifier. The instructions say you should use earbuds to listen to the radio, but I found that my standard stereo earbuds to be off too low an impedance for while the radio worked, all stations heard were very faint – about as strong as you’d hear from a typical crystal radio kit.

Heathkit Explorer Jr. 1st run sticker

I hooked the radio up to a set of PC speakers which helped – a lot. Once I could hear the audio output, I was very pleased with the radio’s performance. The tuning cap is geared and it takes a good five turns of the tuning knob to cover the entire broadcast band. The radio was fairly sensitive and not too selective – again, as you’d expect.

So, was it worth it? For me, sure… but it depends on what you are looking for.

It’s a bit pricey for what you get, but if you want to support Heathkit as it attempts to rise from the ashes, and if you have the $$$ to ‘donate’ towards the cause, it may be worth it.

Heathkit Explorer Jr. Completed w. screwdriver

Here is my take:

The good

  • Very nice quality materials….the PCB, tuning cap, and cabinet were of a quality you don’t often see in kits.
  • Nostalgia factor–from the packing to the manuals, the kit really does capture some of the Heath nostalgia.
  • Level of detail in the step-by-step instructions.
  • Documentation. The manual ends with a very nice feature on radio theory and theory of the different stages of the TRF and how to read a schematic. It’s clearly written for a youngster as it’s complete with drawings of smiley-faced electrons moving through the components and circuits.
  • The radio does work and is a joy to tune across the dial.

The bad

  • Quality control is lacking. It’s hard to imagine a kit ever leaving Benton Harbor back in the day with such glaring errors in the manual (wrong color code, missing steps), or with the wrong size zip ties, etc.
  • Price. Even though the materials are high-end, the retail price seems a bit high.

The ugly

  • I really wish Heathkit had included either a built in audio amp circuit (there is plenty of room in the cabinet to add a simple IC-based amp), or would have marketed a separate audio amp kit. Having an amplified speaker would add a lot in terms of pleasure from the completed kit. Another kit vendor, Peebles Originals, peeblesoriginals.com, sells a nice little audio amplifier kit for use with their regen radio kits. I’ve built it, and it’s a simple straight forward kit. Heathkit could have done this and it would have made a big difference. (I think I’ll try my Peebles amp with the Explorer!)

Overall, I really enjoyed the build and I like the radio. I’m looking forward to see what the ‘new” Heathkit does next.

I applaud Heathkit for making a go at a come-back and will continue to support their efforts by buying and building their pricey stuff – yeah, I’m that guy.

73 de AB1DQ
James


James, thank you for not only sharing your experience–along with errors and omissions–but providing excellent, detailed photos. I can’t tell you how many times I’ve been confused by kit instructions and turned to Google to help me find photos and notes from other builders. Your details will help others attempting to build the Heathkit GR-150.

I hope you enjoy your new Heathkit! You’ll have to let us know how that Peebles powered speaker works with the G-150!

New from Heathkit: the Explorer Jr TRF AM radio receiver kit

HeathkitExplorerJr

The Heathkit Explorer Jr. (Image Source: Heathkit)

Yes, the legendary Heathkit company is back and their first kit is a simple Tuned Radio Frequency (TRF) AM/mediumwave analog receiver: the Explorer Jr.

I knew Heathkit was back in business and under new management, but hadn’t heard any updates as of late. Their president, Andy, just sent a message to the “Heathkit Insiders” group explaining what the team has been up to:

“We’ve designed and developed a wide range of entirely new kit products. We authored the manuals for these kits, complete with the beautiful line art you rely on, preserving and respecting our iconic historic Heathkit style. We developed many new inventions and filed patents on them. We relocated Heathkit, and set up a factory, and a warehouse, and offices, in Santa Cruz, California, near Silicon Valley. We built the back office infrastructure, vendor and supply chain relationships, systems, procedures, operations methods, and well-thought-out corporate structure that a manufacturing company needs to support its customers, to allow us to scale instantly the day we resume major kit sales. All this effort enables us to introduce a fleet of new kits and helps ensure Heathkit can grow, prosper, and continue to bring you great new products for a very long time.”

The Insiders’ message goes into much more detail–I would encourage you to contact Heathkit about joining this group.

The big news in this message was the launch announcement of the Explorer Jr. kit which can be ordered from their website now. The price is $149.95 plus shipping. Heathkit anticipates a 30-day shipping time for the first set of orders.

Here’s a description of the kit from their website:

A Radio Kit Whose Time Has Come.

Again.

When Heath started designing & selling do-it-yourself airplane kits shortly after the Great War, the state-of-the-art in radio was the Tuned Radio Frequency (TRF) design.

A TRF radio was a great deal. If you had a great deal of money. A TRF receiver became a fixture in the homes of families around the world, receiving the news and music AM broadcasts of the day. A family AM radio was a big investment — $100 to $625 in 1929 dollars. (With inflation, that’s $1,400 to $8,700 in today’s dollars.)  Of course, at that price radios also were beautiful. They were made of fine wood, and designed to last. Radios were a visible and attractive furnishing you could be proud to have in your living room or parlor.

Heathkit’s TRF radio is a great deal. And a great deal of radio. This Explorer Jr TM radio is modeled on the original TRF designs, but better. You get to build it yourself. It’s safe and simple enough for beginners to assemble and understand. But it receives AM broadcast stations with performance superior to the vintage radios of 1930.

With the number of Heathkit enthusiasts out there, I suspect this first run of kits won’t last long. The kit trim is available in six colors: Silver, Cranberry, Cucumber Green, Plum Pie, Sapphire Blue, and Tangerine.

Click here to view and order the Explorer Jr on Heathkit’s webstore.

The Ten-Tec Hamfest–and my new (vintage) LS-166/U military loudspeaker

My only purchase at the Ten-Tec hamfest flea market this year, the LS-166/U military loudspeaker

This past weekend was the Ten-Tec Hamfest, which is held each year at the Ten-Tec factory in Sevierville, Tennessee, USA. I’m particularly fortunate in that I live within a few hour’s drive of the factory, so I make it a point to attend the Hamfest each year.

Hamfests, for those of you not familiar with them, are basically flea markets or swap-meets for amateur radio operators and radio enthusiasts of all stripes.  It’s a place to reunite with hobbyist friends and to trade, sell, or purchase new or used radio equipment. The Ten-Tec Hamfest is free, draws a sizable crowd, and what’s more, attendees get the opportunity to try out Ten-Tec radio equipment and tour the factory where their products are made. The Hamfest also coincides with the annual SEDCO DXer/Contester Conference, which is held in the same town, and begins just as the Hamfest winds down.

This year, I had not intended to buy anything. Still, I’m pleased to admit I bought only one item…

The LS-166/U loudspeaker is built like no other–it’s even gun blast resistant! Its rigid cone is well protected by thick metal screen and mesh.

My purchase:  an LS-166/U loudspeaker. This small speaker has been used extensively in military operations around the world. It’s built like a tank, was perhaps mounted in some, but used primarily used in Jeeps, trucks, and on portable radio packs. The case is made of metal and extremely durable. The two watt speaker has a permanent magnet.  It is also fungus, gunblast, and immersion resistant:  if you drop this speaker, you don’t need to worry about damaging it–rather, you may need to worry about the floor (or your foot).

Side view of the LS-166/U: though heavy, its dimensions are only 4.75 x 4.75 x 3″.

The really cool thing about this speaker is that it contains an audio transformer that–via a switch on the side–will allow you to chose between a 600 ohm primary and 8 ohm secondary impedance. The speaker sounds crystal clear, even though mine has obviously received extensive usage. That’s the great thing about military gear–it was designed for functionality, often over-engineered, and certainly built to last!

The LS-166/U is not for listening to music–it was designed primarily for radios that require a high impedance load, and for voice audio clarity. If you’re receiving orders over the radio from your commander, the LS-166/U will punch through the noise from your vehicle and surroundings. It sounds “tinny” if used to listen to shortwave broadcasters, but is actually quite effective when used to listen to amateur radio transmissions and morse code. The 300 Hz to 7 kHz frequency response is ideal for this type of application.

The schematic is printed on the inside of this back plate, which is easily removed with a plain head screw driver

The first rig I hooked up the LS-166/U to was my Hammarlund SP-600, which has a 600 ohm output. Though I know I can hook up a larger, more responsive speaker for better fidelity, there is something rewarding about hearing a speaker that has seen so much service being used once again, and still playing as if new.

As you can see from the photo below, mine lacks the knob on the side of the case.  I’ll be looking for one of these at the next Hamfest–or may just order one from Fair Radio.

If you happen to locate the LS-166/U loudspeaker at your local Hamfest, grab one! There are a lot of them floating around and they’re usually quite affordable–typically between $10-20 US (more if mint). I was lucky to pick mine up for $4. Not only is it an affordable piece of military radio history, but I think it would make an excellent external speaker for amateur radio use during outdoor events like Field Day. Indeed, I think this speaker will weather any radio challenge!

So, what else did I see at the Ten-Tec Hamfest this year? Quite a few classic receivers. Though I didn’t take many photos, I did snap a few gems…

Photos

This aluminum radio speaker reminds me of the external speakers found on radios in the early 1900s. The seller had made a custom wooden base for this one (click to enlarge)

Heathkits, in near-mint condition (click to enlarge)

An antique Marti receiver, the first of its kind I’ve ever seen (click to enlarge)

A close-up of the Marti’s beautiful dials (click to enlarge)

The Kennedy 281 (click to enlarge)

If you visit the Ten-Tec factory, tour their radio museum, housing nearly every radio Ten-Tec has produced. One example is the  SP-325 (on bottom) a shortwave receiver which once served the US government as a training radio. They’re fairly rare, but can be found occasionally on eBay. (click to enlarge)

Heathkit is back in business

Great news for kit builders! Legendary company Heathkit has started manufacturing kits again. Though their first line-up of products do not include radios, they are planning to cater to the amateur radio community as soon as next year.

I would like to believe that the popularity of the Maker community has given Heathkit the ability to re-enter the growing kit building market (it has certainly given Radio Shack reason to continue carrying components).

Here is an announcement from Heathkit’s website:

Thank you for your overwhelming response to our announcement that Heathkit is back into the Do-it-Yourself kits business. We received many great suggestions for kits you would like to build.

We will be releasing Garage Parking Assistant kit (GPA-100) in late September and soon after the Wireless Swimming Pool Monitor kit will be available.

Based on your input, we are looking at developing amateur radio kits. Our goal is to have kits available by the end of year.

Please keep your suggestions coming so that we can continue to bring you interesting, unique Heathkit products.

Now is the time to let Heathkit know you that you want shortwave and amateur radio kits!

You can contact Heathkit at the following address:

Heathkit
2024 Hawthorne Avenue
St. Joseph, MI. 49085
(269) 925-6000 : Phone
(800) 253-0570 : Toll-free
(269) 925-2898 : Fax
info@heathkit.com