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, 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!
Spread the radio love

8 thoughts on “James reviews the Heathkit Explorer Jr. GR-150 TRF AM radio receiver kit

  1. George

    I built my first heathkit (GC1107 VFD clock) in an evening – got it for my 12th birthday – and it still works (I am retired now and in my 60’s) -did have to relace the electrolitic capacitors due to a flickering display quite a few years ago -used mil spec 105 degree ones of course…
    Have restored a HW101 HF transciever (ebay many years ago – silly cheap) now has a digital frequency display – have a look on my website

  2. Ron G

    I was happy to see Heathkit advertising in QST. I looked at their website, and checked out this radio. After reading your review, I think I had the right impression. The radio is nice looking, but not more useful than a simple crystal radio. No amp? No tuning dial? Is it, in fact, a regenerative receive design?
    Way too much money, and hearing there is no schematic with parts values, forget it.

    1. Milo Austin

      Ron, I agree with all your assessment of the radio. No, it’s not Regen, It’s a Tuned Radio Frequency, meaning it just has a tuning circuit and an RF amplifier and detector. Maybe the missing schematic and parts values, while still no excuse, is just a result of being (I guess) their earliest entry. I have the GC-1006 clock which I am just starting to put together, and it has a schematic and all the component values. The zener does not give the voltage/current values, but does give the 1N number so you could look it up. The schematic so far does not have any *material* errors, but it does have errors nonetheless. I wrote Heath about the cost, and they replied with some lame excuse about the type of person they were targeting, and that it was right in line, given inflation, with a similar Heathkit from the earlier time. To me, it’s still just an excuse and is a very expensive radio that is little more than a glorified crystal radio (and even those are not cheap now). They said it wasn’t targeted to someone of my “experience”. What a bunch of hogwash that was. That certainly does not justify the cost.

  3. Doug

    I’m in the midst of putting together a GR152, which is the soldered version of this radio. All the parts are there, and the instructions are very clear. However, one of the leads broke off of the “voltage regulator,” which is shown in the diagrams as simply a Zener diode. Much to my horror, I realized that the voltage value of the Zener is not given – only the Heathkit part number, which is useless. So a simple part that I probably already have or could easily get has suddenly stopped me in my tracks. I’ve written an email to Heathkit asking for the component value – there is no support section on their website. I could find no listing of Heathkit parts online that would tell me what voltage value is needed. Why didn’t Heathkit include a full schematic with component values as part of the documentation? What kind of morons do they think they are selling to, or are they trying to make an extra buck by forcing us to purchase replacement parts only through them? Having sold the kit for $150, I would think that they would not try to squeeze any more money out of us in such an underhanded way.

  4. Ed McCorry (KI4QDE)

    This is somewhat disappointing. As someone who has built 20 Heathkits including the console TV and robot back in the good ole days,(and I still use most of them) I hope this is just kind of a beta test to get back in the market and not the wave of the future. This kit is not very impressive. What’s with the nuts and bolts? It’s almost like the Radio Shack electronic labs where everything was connected with springs. It seems from the review that this kit is made for the inexperienced builder with no need to learn soldering skills etc. Which is okay if that’s the audience your marketing to. The old manuals had a lesson on soldering in the first few pages.

    Heathkits were expensive back in the day, but I always found them worth the money because of the kit building enjoyment and value add with functionality that didn’t exist anywhere else.

    I hope they succeed in getting back up to speed because kit manufacturers are getting sparse and then I’m sure I will be buying more kits once they have something that I would like to build and felt was worth the cost. Just my two cents.

    1. Dave H

      Just like we all had our “first Heahtkit” to learn on, so does the company that now own the label. They had to start somewhere, and a simple-to-fabricate kit like this using easily sourced parts means they could focus more on getting the rest of the business up and running. And, just like us, the things they learn from the first kit make it easier for them to move on to more advanced designs.

      I hope they do well and can continue. I think there’s a place for decent kits in the hobby electronics world, and I’d be perfectly happy for them to bear the Heathkit name again.

      1. Robert

        I am with you, Dave. I have seen a lot of negative reviews of the kit (not based on quality, but on price, choice of first kit, etc.)
        My excitement was to see being offered as a kit from a legendary company, with hopes for more advanced kits like the “old days.”
        I want them to succeed, and I want to have the opportunity to experience something of what many other hams got to experience with the original Heath Kits. I wish them all the best.

  5. DL4NO

    What a time! My IG-1271 function generator is still in my shack and about a dozen homebuilt Heathkit units are in the cellar. It still works, only the front got yellow over the years.

    Heathkits were never cheap, especially here in Germany where they had to translate the manuals, pay customs and so on. But I always enjoyed them – when building and later. The assembly manuals are still the reference to beat.


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