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AMI #1670

Licensed since 1972 **Celebrating 40 years as K5UJ**

Change to QSL policy--see below*

The photos show my Hallicrafters HT-20 which I finally got around to finishing in spring 2016.  The rig came to me from Jon Rosner WO9S who was the first owner of the rig (purchased on Radio Row in NYC!) and ran it as a Novice in the early 1950s and on until more modern gear became available.  In 2009, Jon decided to let it go and I purchased it.  KB9YSJ and I carried it into my basement and at 110 lbs., I was glad Hallicrafters put handles on it (imagine hauling it on to the beach at Clipperton Island in 1952).  It didn't take long to get the front panel off and I sent it out to Bob W0YVA to be redone.  It came back looking great and then the rig sat in my basement on a table for 6 years while I worked on other projects.  I finally made myself get back to it and finish the job beginning in December 2015.   By then I couldn't remember how the front panel went back on and I had made the big nooby mistake of not taking photos before disassembly.  Thank heavens Bob W9RAN had plenty of photos of his HT-20 on-line including one key shot of behind the front panel looking down from above, that saved my bacon.   With the front back on, work resumed on nights and weekends over the next few months. 

There wasn't much to do.  I replaced the power cord, fuse holders and rear panel UHF jack and feedline run to the jack on the underside.  The usual re-cap was needed with a few micamolds, electrolytics, other paper wrapped caps and molded plastic bumble bee caps getting tossed.  A few stressed out looking carbon resistors had to go too.  I also removed the old keying mod. Jon had done and put in a front panel "send receive" toggle switch to switch relay coil v. to an open frame T/R relay I mounted underneath.   The low B+ supply stock, never had any bleeders and I fixed that with a 60K w.w. resistor.   The 5R4s had traces of carbon tracks on their bases which I removed with a Dremel.  One more little extra I added was "negative cycle loading" i.e. a 5 K 20 watt resistor from high B+ to ground at a junction between the modulation transformer secondary and the final PA.  I put a string of reverse biased diodes adding up to 3 KV PIV between the junction and the resistor.  This is so that if modulation takes the final B+ down to zero v., the diodes conduct and the 5K ohm resistor is there to function as a load on the modulator.  

 On top I replaced some micas and the parasitic suppressor and the rig was ready for show time.  Two things should leap out:  The peeling paint and warped pot metal bezel.    From what I've heard, the peeling paint was due to Hallicrafters not putting on a primer first on the front panel steel.  W0YVA took care of that.  The meter frame was cast with pot metal that evidently had insufficient stress relief in the casting so eventually it warped and cracked.  The composition of pot metal is what causes this.  At first I operated the rig without any bezel at all (I'm not overly concerned with appearance compared to performance).  Greg WB9DNZ stepped up to the challenge with his fantastic wood working skill and crafted a wood frame with nothing more than my measurements and photos, using oak and a black gloss paint and it dropped right in.  The fit couldn't have been better and it really dresses up the rig.

The HT-20 is in the 100 w. class with the EFJ Viking 1, and the Collins 32Vs all of which ran the 4D32 as a final tube.  It was introduced in 1952, listing at around $450 and didn't sell well.   The Viking 1 at $200 less in kit form, beat the pants off it in the market place, while well heeled hams went for the Collins with the PTO built in (and a cabinet crammed like a fruitcake with parts to match the A-line receivers).  But if you could afford it, the HT-20 was a sleeper.  Designed for other than just the ham market, it was built to transmit with no time limit so the final had a fan on it, and the power supply iron was all over-sized.  Put the HT-20 into transmit and leave it for 20 minutes and the h.v. supply transformer is barely warm.  Being more than just a ham rig, the HT-20 was designed to tune up on any frequency from 1700 kcs to 30 Mc.  This means if you have a signal source to excite it, you can run it on the (still new to me) WARC bands.  In fact, the night 17 meters officially opened to Americans, the first all-American rig on the band from the U.S. was a HT-20.*   Built to have absolutely no emission from the rig apart from the antenna, to prevent the dreaded TVI of the early 1950s, the HT-20 was heavily shielded, all of which I removed and put aside for safe keeping.  What about criticisms?  Two come to mind:  If Hallicrafters wanted to go all out and make the ultimate 100 w. rig, they could have dispensed with the phenolic coil forms and band switch wafers and gone with ceramic as EFJ did with the Viking 1, demonstrating that if you have the factory that makes ceramic parts, you have some advantage when it comes to transmitter manufacturing.   The other weak link in the rig is the low v. supply transformer, which also supplies 5 and 6 v. filament current for the rig.  That poor little guy has a lot of work to do and does get warm.   Some hams might not like the need for an external VFO.  In my opinion, rigs that do not have the VFO built in are better, because you can power the VFO separately and leave it on while the transmitter is off.   On weekends when I am at home, I'll often leave my VFOs on for 48 hours so they stay nice and stable.  With a DX100 or Ranger, if you want that you have to have the whole rig running, unless you want to re-wire things with a separate VFO power switch (which isn't a bad idea if you ask me). 

 As I often do with my equipment, I run the HT-20 naked, i.e. out of the cabinet with no covers, because I like to see the works in action in my equipment, which is a big part of the fun of tube gear for me.  It also makes it a lot easier to work on, if you don't have to get a rig out of its cabinet.   I mostly run the HT-20 on 75 and 40 m. phone with a Youngstown D104 right into the rig, which is either crystal controlled or run off a Johnson 122 VFO which you can see sitting next to it in the photo, home-brew power supply on top.   In the second photo you can see how the rig looked when I first brought it home, a before/after look see.



*Hanlon W8KGI ER #68 p.20 Dec.1994

I've had a request to return some photos of my Eldico TR-1 to this page.  I'm working on the TR-1 at this time.  The progress is slow because I have to work, and do chores and the usual obligations of life, and also because I'm not in a hurry and enjoy working on gear and trying to do a good job.   For me a lot of better radio work comes from going slow.   I'm working on the power supply chassis and I hope to have it ready for operation soon.  Then I want to move on to the RF/audio chassis.  I need to make a wiring harness to connect the two and eventually put the pair of chassis into a 3 foot tall rack I have.  RF and power supply chassis below:

At the bottom of this page are more words and links to information about the TR1 which I like to think of as the poor man's Meissner 150B hi hi.

Antennas: Two dipoles at 50 feet center fed with 600 ohm ladder line and a Johnson KW Matchbox, one 130 feet long for 40 and 80 meters and the other 33 feet long for 10 - 30 m., and 1/4 w. verticals for 75 and 160 m. (50 foot high inverted L on 160 tuned with modified Unique Wire Tuner).  Both verticals fed with LDF4-50A, and co-located over a compromise ground system of 102 radials ranging from 10 feet to 120 feet in length.    Several receive antennas, among them Hamstick dipoles and small tuned coaxial loops.

Rig: Yaesu FT1000MP Mk V driving a Ten Tec Centurion.  Early 1960s homebrew rig, 2x3-400Z modulated by 572Bs.  Knight Kit T50 CW rig.  Hallicrafters HT-20.  Collins 75A-3, RCA CR88 receivers.

In the early 1980s I pretty much went QRT when I went off to college, following four years in the Army, and what I thought would be a few years off the air wound up being 18 what with graduate school, and several moves. Fortunately I kept renewing my license and when I figured I had finally settled down for a few years, I decided to get back on HF. That was in 2000 and I found a lot had changed; there was a lot to learn, but one thing that had not gone out of date was a good AM ragchew and that's what I enjoy today.




Manuals etc. starting with the incredible Meissner 150-B, a genuine "boat anchor" ...

Instruction Book for Model 150-B Radio Transmitting Equipment
Consisting of Type 02520 Radio Transmitter and Type 02433 Exciter Unit

Output: 150 Watts Radiotelegraph
Output: 150 Watts Radiotelephone

Manufactured for Signal Corps U.S. Army
By Meissner Manufacturing Co.
Mt. Carmel, Illinois

Order No. 13759-PHILA-43 Dated: October 18, 1942

77 pages, 8 1/2 x 11 inches, one fold out schematic (in two pages).

As many know, the Meissner 150-B is one of the more remarkable rigs manufactured in the golden age of ham radio.  It seems everything made by Meissner was built to be dropped off the top of the Empire State Building and still work, and the 150-B, designed for the Signal Corps, looks as if it could have done double duty as a pile driver.  You won't have to own a 150-B (I only own the exciter unit, a military version of the Signal Shifter) to find the manual interesting and enjoyable to read, provided you appreciate vintage AM and CW gear and the style of writing of the day.

At ~350 pounds, the transmitter unit is a boatanchor with a capital B (maybe that's the meaning of the B in the model number  :D) but a restored and operating 150-B is a rare thing of beauty to behold (four 866As!).

The exciter schematic is also on the main schematic page and the manual covers the exciter, so this manual is probably of use to Signal Shifter owners also.

Additional Meissner 150-B information and photos of the rig in all its gray wrinkle glory can be found here:


Wayne Steiner N0TE authored an article on restoration of the 150-B which was published in the September 1996 issue of ER no. 89 on p. 24.

meissner150B.pdf Meissner 150B pdf manual 28MB
lowres150B.pdf 13.4 MB
orig150B-schem.pdf Original 150B schematic PDF 939 KB
orig150b-schem1page.pdf 150B schematic on one page 4.5 MB

Other items:

AR88 promotional brochure 1.8Mb

NC300FSnotes.pdf National NC300 field service notes 2.12 MB
groundconductivity.jpg FCC Ground Conductivity map 596 KB
Doty-Radials.pdf 804 KB
ranger1intro.pdf EFJ Ranger introduction 8.98 MB
ranger1operating.pdf Ranger operating manual 15.3 MB
WRL755.pdf WRL 755 VFO manual 3.3 MB

Finally the Eldico TR1, a kit ham rig, the only ham rig ever made to use the 813. See Nov. 1950 QST for full page ad.:

W2UOL, Mr. Donald Merten, located his Eldico Company in Douglaston (Queens) L.I. N.Y. in the late 1940s.  His Eldico TR1 was an open dual-chassis rig--power supply (2x866A) on one chassis; audio and RF on the other.  It was meant to be run on a table side by side out in the open  :o   This was shortly before TVI became a big problem for hams.  The parts are indeed of high quality from a day when nearly everything in radio was of relatively high quality, so it is nice to have the components on "display,"  such as the Raytheon filter choke in the power supply, the 866As, and the 813.  The business philosophy of Eldico seems to have been to provide hams on a limited post-WW2 budget, a means of getting on phone with a fairly powerful transmitter.   Eldico also owned another business called Surplus Radio, which may have been the source for some of the TR-1 parts such as the modulation transformer.

Modulator 2 x 811A; RF single 813 plate and screen modulated class C.   Mod iron ART13.  1.5 KV B+ modulator and RF.  This rig was sold as a kit in 1949 for $179.   Bands:  80, 40, 20, 15, 11, 10 m.   Link coupled output with B&W TVL plug-in coils and B&W butterfly air variable cap.  Eldico advertised 300 w. input on phone.   This is (to me at least) an extremely interesting design.

Copies of the manual are available from Pete WA2CWA d.b.a. manualman.com, but the manual lacks the schematic.  It turns out the schematic is a large "blueprint" style sheet measuring around 2' x 3'.

Thanks to the effort of Al W1VTP who kindly photographed his schematic and sent it as a pretty clear .jpg file, I have with his permission put this up on the web.   This is especially noteworthy since Al is in the middle of moving.  This is real AMer style support and cooperation.

John K2TQN did some contrast enhancement and sent that result to me as well.

Unfortunately the current files are difficult to print out on a regular typing paper size printer but viewing on a monitor screen is not too bad (and sure beats no schematic at all).  Al's file gives the original look which I like but in cases where higher contrast is needed John's .jpg version helps.  

I find the rig's design elegant and a possible basis for a homebrew effort if an actual TR-1 is not available.  N.B. The TR-1 is different from the 1953 TR-1TV, which used a 5-125 PA in a cabinet with a different power supply and output tank.  

This is a great supplement for the TR1 manual reproduction.

TR-1ps.jpg 205 KB
TR-1rf.jpg 205 KB
TR-1rf2.jpg 204 KB
TR-1schematic-enhanced.jpg 2.69 MB
TR-1schematic-enhanced.pdf 2.7 MB
TR-1schematic.jpg 1.78 MB
TR-1schematic.pdf 1.85 MB

*I do not reply to eQSLs. Due to work load, effective 21 June 2004, I am no longer reply QSLing contest-computer printout generated QSLs. By these I mean cards that have contact information automatically printed on them or on labels that are stuck to them and mailed out with no handwriting, or even a signature on them. I regard these as machine generated QSL junk mail. I also no longer reply to QSLs for QSOs that took place more than five years ago.

8243564 Last modified: 2017-07-29 17:19:19, 18764 bytes

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