HART 25 ,One tube transmitter , HART Transmitter , QRP Transmitter

Back in 1958 I received my novice license at age 16 . I saw the Hart 25 article in the April 1955 Popular electronics magazine and built it .I made my first CW contact with that transmitter and a BC-348 WW2 receiver and In 2013 I built another Hart 25 just for kicks using a 6V6 tube instead of the 6W6 because I had a 6V6 and made quite a few QSO's with it now in March 2018 I took it to Colorado and was able to have a QSO with my friend in Mishawaka Indiana a distance of 1200 miles on 80 meters CW what a thrill with 5 watts from a one tube transmitter and a simple dipole antenna . The elevation was 9100 feet of course that helped. Code is the best mode . 73 Bob

[@michaeldavidheit]

Woodland Park, Colorado?? I lived there for 12 years. My late wife Laura is buried there. Great video sir. Thank you, Mike AD7VV

[@wansolve2036]

I built one of those from a kit in my High-School Radio & TV shop class back in the early seventies along with a one-tube regen receiver. The transmitter worked great up through a 40m dipole about 30' high over the shop. We made a few contacts with it but the regen recvr was horrible to use. Then our instructor broke out a Collins R-388 from the storage room and it was awesome using that for recv, very stable. Thanks for the memories!! I may dig through the junk box and see if I can build that Harp-25!

[@billlaut608]

BC-348! That was the radio my late Uncle Ed gave me back in the 1970s, the exploration of which introduced me to amateur radio. I still have it, and it works great to this day! (And while I never could master the code in my youth, I did get my ticket five years ago. Someday I'll get a Heathkit HD-1410 paddle and learn it!) Great video, Bob. I always enjoy watching your videos and learning from them!

[@tomcroley7084]

Very nice home brew tube rig Bob, looks like a great project. I will find that article. Thanks for sharing. 73 AK4DC

[@janetwinslow2039]

Nice nostalgic video. Thanks. Looking through the old magazines of that era shows how things have changed. Modern magazines are 'sterile' by comparison. All these old magazines have pages of fascinating content - so much stuff to build. I'm from the UK and old copies of Practical Wireless, Radio Constructor, etc. have pages and pages of much more interesting content than their modern equivalents. Maybe the G-QRP Club's publication 'Sprat' is one exception...

[@m0dad]

Hi Bob, very nice project and looks very well built. I love to see these vintage homebrew transmitters.

[@robertsumption1243]

M0DAD Yes I have really enjoyed this little transmitter . Last spring I took it to my daughters house in Woodland Colorado . Strung a 80 meter dipole in the pine trees at 9100 feet on the mountain and worked my friend in Mishawaka Indiana 1100 miles away on CW he was really surprised as I was . 73 Dave

[@jerrydaugherty3781]

Hi Bob thanks for the memories, I was first licensed in 1958 as KN9PFV at the age of 13. Lot of fun back then. 73, W9FS

[@robertsumption1243]

Yes Jerry Its those memories that prompted me to build this transmitter . I was 16 when first licensed as KN9VYE also in 1958 . 73 Bob

[@warplanner8852]

Super job and wonderful memories, Bob! Still have my novice crystals for 80: 3720 kc, 3730 kc, 3730 kc. Also, remember that you could use an octal socket to hold two FT-243 crystals snd switch between them. Thank you for sharing this! 73 de then WV6KJK, now K6WHP dit dit

[@robertsumption1243]

Yes ! War Planner you know the old Harvey Wells TBS-50 transmitters have an octal tube socket the flat brown phenolic one mounted behind the front panel for the crystal socket . 73 Bob

[@warplanner8852]

Robert, I do remember! Also thinking of the XMTR that appeared in the ARRL handbook circa 1958-1964. Have in mind to build the classic novice station that was pictured on a QST cover with the regen receiver, the transmitter with the J-38, and the power supply made with the pine firring strips that practically invited death by electrocution. Hi hi. de Bill, k6whp dit dit

[@ktheis1]

My first transmitter was the Hart 65 from a popular electronics magazine article.

[@hs1754]

Yes, Morse code is the best mode and does very well for neurons! CW forever!

[@khalidtarawneh2289]

that TX sounds great and looks neat. Great Homebrew skills u got ther 73 from Amman JY

[@jeromewysocki8809]

I'm working on building a similar transmitter. It will use a 6AG7, or a 6CL6 tube instead of the 6V6. It will also have two 0B2 voltage regulator tubes to help eliminate chirp. A pi-network output will be used to better load the antenna, and to reduce harmonics. I got all of the parts from my junk box. Hopefully, I'll have it build and one the air in a few weeks. ... Jerry, KC9JXE

[@robertsumption1243]

Brian , i like that key works good 73 Bob

[@retro440]

Nice video, Bob. Wow, you had a BC-348 as your FIRST receiver?? You were big time. My first RX was a Hallicrafters S-40B. As a General , I UPGRADED to a BC-348 and it was a Cadillac compared to the S-40B My first TX was a borrowed Adventurer. 73, Mike

[@AlreadyThere1965]

Nice video, interesting I just got one of those keys this week too.

[@stationvictormike3415]

I downloaded that copy just now. Thanks.,, I'm looking into building one. I do tube radios as well. I acquired a lot of vintage dials and tuning capacitors of all kinds and headphones. A good supply of them.. I salvage parts as well.. I did purchase a New old stock Transformer box with different voltage connections for filament and plate at Duke city Hamfest this yr as well..

[@robertpritchard1480]

I picked up a Hart 25 at Dayton a few years ago. I was looking for parts to build a Copy of the Ameco AC1 and found it a box of parts under a table. The guy didn't know what it was but it looked like it had a few parts I could use. While walking around with it in my hand, a fellow stopped me and told me it was a Hart 25. I couldn't find and information on at the time but a year or so latter if found the article in Popular Electronics. The one I have looks exactly like the photo in the magazine article. I put a few new caps in it and put it on the air in the Novice Rig Roundup.

[@scharkalvin]

With a 6V6 you don't have a 'Hart 25', more like a Hart 15. You need a 6L6 to get 25 w input.

[@facundobresan1009]

Y el sonido? nunca lo encendiste!

[@aheriady]

YC0LOG, cq cq from Jakarta

[@robertsumption1243]

Thank you Jakarta Adrian Engineers ! This Hart 25 transmitter with 6V6 tube I took to Woodland Park Colorado with a 40M dipole and worked my friend back here on CW with it what a thrill that was 1100 miles on 80M cw Happy 2021 ! ...73 Bob

[@robertsumption1243]

No it was 1200 miles Hi Hi 73 Bob

[@gy.p_gordonfreeman]

For anyone who can't find the magazine, here is a link: worldradiohistory.com/Archive-Poptronics/50s/55/Pop-1955-04.pdf