The Heathkit GR-81 Economy SWL Receiver

[@Beemerider1150r]

This was my very first build from Heathkit. In 1970 I was 15 and ordered one of these with my grass cutting money. I remember it was around $27 or so. I remember taking it to my science class as part of a project. Your review brought back many memories. Thanks!

[@terhunetreecare]

Around 1972 my father gave me this radio kit for Christmas. I spent most of my time listening to Radio Moscow and the BBC. Thanks for the memories.

[@timinbovey]

Nice video! When I first got my ham license in 1969 (I was 11 years old) my elmer (my friend's Dad, who mentored us through getting our licenses) passed his Son's GR-81 on to me - his Son had moved up to a more modern receiver -. It was my first ham receiver, which I used along with a 25 watt tube morse code transmitter I built from plans in a library book. This was my ham receiver with which I made many contacts for my first year or so as a ham, until my Dad bought me a Hammarlund HQ-110 through an ad in the local newspaper. Still have the GR-81 too. I think I'll save it from the attic and see if I can get it going again! Thanks for the video.

[@captlarry-3525]

Jeff, thanks ! Never had this one. All regens can be critical in adjustment.. but one learns. Well designed RF amplifiers ahead of a regen detector really improves their capabilities. Heath was populated by execellent radio engineers. It is no accident that one of their most poplular and successful kits.. the sixer, and twoer used the super regen receiver which made operating on 6 and 2 meter VHF ham bands cheap, easy, and tons of fun.. for literally 1000's of hams. The regen and super regen receiver is a very elegant and powerful receiver. They have incredible sensitivity, and can receive CW, SSB, and AM equally well. They opened the world of radio as a truly practical thing. Eclipsing in every way the crystal detector. Major Armstrong... the seminal inventor of modern radio began his famous contributions with the Super Regen, followed by the Super Het, and then Frequency Modulation. Great advances were possible because of the Regen, and the combination of the regen and the modulated oscillator made the transceiver possible in the late 20's and that opened up the world of VHF. So these are extremely important historically.. and a hell of a lot of fun to build and to use ! Anyone who sees the elegance of simplicity and economy.. and is willing to learn a little of the ART of radio operating.. embraces the regenerative receiver.

[@dougkubash8673]

I assembled one of these back in the old days! I had to take it in to the Heath service dept. - installed a diode backwards and some bad solder connections. Heath didn't charge me a cent for the repairs.

[@bobclarie]

Well done, sure brought back my early years in radio. I built a Heathkit DX-40 when I got my novice ticket. Also built a Knight Kit Span Master regen. receiver. Fun times. . .

[@KennethScharf]

I picked one of these up in 'as-is' condition for a few bucks at a hamfest. It was missing the tubes and the power transformer. I decided to rebuild and modify the circuit. In the mid 1960's Popular Electronics had an article on building a two tube regenerative receiver using 12AT7 and 6AK6 tubes. One section of the 12AT7 was used as a reflex grounded grid RF amplifier and common cathod AF amplifier. The other section was the regenerative detector. The 6AK6 was a low power audio output stage. A small power transformer with 125v @ 15ma, and 6.3v at 600ma secondaries was used. I had one of these small transformers in the junk box. I used the original tube sockets for the two tubes, but the 35W4 was replaced by a 1N4007 diode. I also cut the shaft of the main tuning capacitor shorter and installed a Jackson Brothers ball bearing vernier drive between it and the front panel. This reduced the speed of the main tuning. With these mods the power consumption of the radio was reduced and it still worked quite well. The reflex rf amplifier isolates the antenna from the tuning circuits and reduces 'suck out' of the regeneration at various points on the dial. Eventually I sold the radio, as I built a few other regenerative sets.

[@Hunkiralyfi]

One of the best reviews ever on youtube...

[@nobodyyouknow222]

rare radio I haven't ever seen in person... nifty and worthwhile for the beginner. I will look for your book.

[@handsomeclem208]

The headphone jack was designed for use with 2k high impedance headphones; had lots of fun receiving lots of the then big gun ISWBC stations, plus SSB voice ham and since this was the early 1970's, even transcribed weather broadcasts from Cincinnati Lunken Airport station LUK on 335 kHz longwave.....

[@patrickwall8517]

As well as being economical it was meant to introduce people to shortwave, ham radio, and kit building.

[@russphilly]

still have this radio, from 1968

[@Varianna12]

Superb!!!

[@BrokebackBob]

That fuse holder with the piggy-back spare is a mod.

[@timsmith2811]

I just purchased a good GR 81 on eBay - after checkout and safety inspection, it works well on broadcast with short wire antenna, but is dead when a 25 ft antenna is connected to the long antenna terminal. All coils have continuity and the radio will receive a signal from an RF generator applied to the long antenna terminal. Strange!

[@jefftranter]

If it is not working well on shortwave bands C and D, there could be a problem with the bandswitch wiring. A ground connection as well as an antenna wire is recommended. Check reception in the evening as as there may not be much shortwave reception during the day.

[@timsmith2811]

@@jefftranter Jeff - thanks, checked all that. The radio does receive signals from an RF generator on all bands. There is some activity around 7 MHz at night and the AM band does pretty well with short antenna connection. Unfortunately I don’t have the room or space to wire up a 100 or so ft antenna. Overall performance is roughly similar to my Knight Span Master.

[@danvanlandingham3854]

I've seen these and the Hallicrafters Sky Buddy II sets on ebay and they cost more than any of the later Heathkit or even earlier Hallicrafters sets such as the S 38 series or the similar 5R10 models.These sets sold for no more than $24.95 to $39.95 new.I remember them from ads in Boy's Life magazine(the Sky Buddy II).I've gotten better Heathkit sets for far less-these sets for for as high as $200.I just bought a Heathkit SW 717 for $40.

[@captlarry-3525]

I wish this had been the first radio I built.. instead of the Heath AR-3 super het ( which never worked, and which at 12 I had no hope of fixing). I think this would have been more successful, and really a more honest cheap radio.. than the crummy AR-3.

[@gregorymalchuk272]

How did they expect you to align the thing and get it working without a signal generator?

[@bootsyaaron]

Mine does not have a fuse holder, but it works nearly the same.

[@jvolstad]

Is that "Charlie" I heard on your radio?

[@stevecafiero2]

Great video! I built this as a kid, one of many Heathkits I was privileged to make. I just finished the restoration of the stereo receiver I built with my dad in 1970. Check out kzbin.info/www/bejne/aYrXnnRpoMp5isU

[@nor4277]

What I would love is to find one of these still in disassembled state so I could build this my self,that would be amazing ,so if anyone has that for a reasonable.price I would love to buy it ,or any other tube radio disassembled .or even assemble if the price is reasonable

[@nor4277]

I miss health kit.There hasn't been anyone to sell these kind of kits,if anyone no,s of any company that sell a.m. tube type radio kits,or if you have one built or better yet inbuilt ,email me .