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Author Topic: The Class D License  (Read 3521 times)
N2EY
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« on: March 26, 2010, 03:19:39 AM »

From the Historical Trivia Department:

Before WW2, anything over 30 MHz was considered "the ultra highs". Television was there, and early FM broadcasting, plus radar. There were ham bands at 5, 2-1/2 and 1-1/4 meters, but the technology was so new that regulation pretty much stopped at 300 MHz. Most use of the spectrum above 30 MHz had developed in the late 1930s and was new or experimental.
 
Wartime developments in radar and VHF/UHF communications advanced those technologies rapidly. The radar that detected the incoming Japanese planes heading for Pearl Harbor operated on 112 MHz and took up several large relay racks; by war's end there were airborne radars in mass production that were a tiny fraction of that size and weight, and which operated at 100 times that frequency.
 
There was concern that amateur radio not be left behind in the post-WW2 development of VHF/UHF/microwaves. Postwar regulation resulted in lots of new allocations, including new ham bands all the way up to 21,000 MHz, but it was feared that if hams didn't use the new bands, they wouldn't last.
 
There were many returning servicemen who had worked with radar and other new technologies that might want to use what they'd learned in Amateur Radio, if they could get licenses. The idea was that these were folks who would be more interested in experimenting than in general operating.   

US amateur licenses back then were in three classes: A, B and C. All required 13 wpm code tests (send and receive) and a 50 question written exam on theory, rules, etc. Class A also required a second 100 question exam on advanced techniques. Class A had all amateur privileges while Classes B and C could not use voice modes on the ham bands between 2.5 and 25 MHz. Class B and C were the same except that Class C was "by mail" using a volunteer examiner.

Some thought it would be a good idea to have a new license class specifically aimed at microwave experimentation. So in 1946 and 1947 the ARRL leadership advocated a new "Class D" license, for 1000 MHz and above. The Class D would have a written test focusing on microwave techniques - and no code tests at all. The radio treaty of those days made an exception about the code test for licenses that only allowed operation above 1000 MHz, so it would be legal only require FCC approval.
 
The ARRL Board of Directors supported the idea so much that in QST for March, 1947 there was a multi-page editorial giving the pros and cons of such a license, safeguards against abuse, etc. That issue included a special insert with a postcard that hams could cut out and mail in to Hq with your opinion. ARRL asked for the opinions of all hams, not just ARRL members.
 
But it appears that despite all the promotion, the hams of those days thought a no-code-test license to be a very bad idea, even if it were restricted to microwaves only. 

The Class D idea was kicked around and modified over the next few years. Eventually it became the basis for the Technician license, which was created in the restructuring of 1951.

The 1951 Technician required 5 wpm code tests and the same written exam of the General and Conditional. But it gave only privileges on 220 and higher. In those days (early 1950s), there was little or no ham gear manufactured for the bands above 2 meters; a ham wanting to get on the air there would have to homebrew or convert surplus.

The Technician wasn't too popular at first, but when 6 and 2 meters were added the number of Technicians grew more rapidly.
 
See QST for March, 1947, "It Seems To Us".

73 de Jim, N2EY
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AA4PB
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« Reply #1 on: March 26, 2010, 04:58:48 AM »

"Class A had all amateur privileges while Classes B and C could not use voice modes on the ham bands between 2.5 and 25 MHz"

So incentive licensing began much earlier than most people think.

Do you know what year 6M was added to the tech license?
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N2EY
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« Reply #2 on: March 26, 2010, 09:51:25 AM »

AA4PB: "So incentive licensing began much earlier than most people think."

I don't know about "most people" but here's the history:

The "ABC" license system dates from the early 1930s at least. Under it, all US hams had access to all amateur frequencies at full power, but voice operation on the bands between 2.5 and 25 MHz required the Class A.

Getting a Class A took a bit of doing because the exams for it were only given at FCC exam points. There was no by- mail equivalent like the Class C was equivalent to the Class B. This was a big deal for folks who didn't live near a major city with an FCC office, particularly in those pre-interstate-highway times.

Also, if a Class C ham wanted a Class A, s/he had to retake and pass the Class B exams (code and theory) from an FCC examiner before even being allowed to try the Class A.
Class A also required a year's experience as a ham, you couldn't get one straightaway.

But note that a Class A didn't require higher-speed code tests, only an additional written exam.

Our current license structure dates from the restructuring of 1951, which was the result of 5 years of discussion and proposals. The changes of that year renamed the ABC licenses as Advanced, General and Conditional, respectively, and added three new classes: Novice, Technician and Extra. No changes to the operating privileges of existing hams; full privileges required an Advanced or Extra. No new Advanceds would be issued after December 31, 1952, either, although existing Advanceds could renew and modify their licenses as long as they wanted.

The Extra was intended to replace the Advanced, and had higher requirements: 20 wpm code tests, a more-advanced written exam, and a 2 year experience requirement. FCC said that some new privileges would be reserved for Extras only, but did not specify what they would be.

What this did was to raise the bar considerably for full privileges. As can be imagined, there was a rush to get an Advanced in 1951-52 before the license was closed to new issues. Some hams got the Extra, "because it was there", and in anticipation of possible new privileges in the future.

But in mid-December 1952 the FCC had a complete change of mind. It was announced that effective mid-Feb 1953 all Generals and Conditionals would get full operating privileges, which effectively eliminated any operational reason to get an Advanced or Extra. In following years, when US hams got 15 meters and when 40 got a 'phone segment, the new privileges were given to all US hams except Novices and Technicians.
So from Feb 1953 to Nov 1968, 4 of the 6 US license classes had full operating privileges. There were effectively only three levels of license: Novice, Technician and General/Conditional/Advanced/Extra.

In the event, there weren't any new privileges added for Extras in that time.

From the early 1950s to the mid 1960s, the number of US hams more than doubled, from about 100,000 to about 250,000. Many if not most 1960s hams did not know that the license structure they were used to wasn't how things had always been. Thus the idea that "incentive licensing" was a new thing, when it really was a return to how things had been before - as far back as 1930.

AA4PB: "Do you know what year 6M was added to the tech license?"

I'll give you the exact date: April 12, 1955.

What happened was that in 1954 W5FXN, James M. Price, and Tom A. Walker (call?) petitioned FCC to open 6 and 2 meters to Technicians. This proposal became an FCC docket and NPRM. Comments were received from 18 amateur organizations and over 125 individuals. FCC decided to open 6 meters to Techs but not 2 meters, based on the comments, which showed support for Techs on 6 but not 2. The ARRL supported 6 meters for Technicians but opposed letting them on 2 meters for the occupancy reason.

The concern was that 6 was underutilized, in part due to its proximity to Channel 2 and in part due to lack of war surplus that could be easily converted to 6 meters. (The popular SCR-522 and VHF ARC-5 sets got a lot of hams started on 2 meters).  2 meters, OTOH, was very popular with hams then, and it was felt that allowing Techs there would not help the 6 meter situation. Ironically, Novices of those times had some 2 meter privileges.

Techs eventually got access to 2 meters, but in stages: 145-147 MHz in 1959, 145-148 in 1972 and the whole band in 1978-79.

73 de Jim, N2EY





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N3DF
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« Reply #3 on: April 01, 2010, 06:19:24 PM »

Whenever possible, I refer to condensers, megacycles and the Class A phone bands.  

"Incentive licensing" predated the A-B-C  licenses scheme.  It started with the Amateur Extra First Class license and the Unlimited Radiotelephone endorsement, both of which were grandfathered into Class A.  

Neil N3DF/Miami
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Neil N3DF
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« Reply #4 on: April 01, 2010, 07:56:28 PM »

Interesting thread.  When I was first licensed in June 1956, with a Novice license, I did not have access to 6 meters.  Many of us who were Novices, also acquired the Tech license for two reasons.  One, we wanted to get on 6 meters with the popular Gooney Box rigs of that era. The other was that the Novice license was good for only one year and could not be renewed, while the Tech license was good for five years and could be renewed.  So we took the Tech test to "hold onto the call sign."  My dual call then became KN4JSG (Novice) and K4JSG (Tech) depending upon which frequencies I was using.  This allowed me to borrow a CD Gooney Box and get on six meters.  

By the time I got my Tech license, sometime in the fall of 1956, I think Techs must have been allowed on two meters, but I don't recall for sure.  I was not on two meters at the time, but used the Novice on 40 CW.

It was the ARC-3 that got me on two meters.  That was the 8 watt, 8 channel 28 volt transceiver, crystal controlled but auto-tuned.  Ran it off a modified heavy duty charger that delivered 24 volts at 40 amps.  It was AM, used mechanical autotuning, but if you tried the autotune it pulled around 60 amps during tune cycle and that would blow my charger.  But it could be tuned manually by means of a plugin external meter. It could also run from a 24 volt dynamotor, but I had removed that.

I also had an SCR522 on two meters, and later a Heath Twoer and a Heath Sixer.  

The Tech license was intended to encourage exploration and development above 50 mhz.  That is why it had a sort of technical exam, identical to the General.  It was not a "push to talk" license as it is today.  All of the Techs I knew well into the early 1960s were experimenters.  There was a 220 mhz net in my area and all of the equipment, both transmit and receive, was homebrew.  Some of them used down converters to standard SW receivers, but the converters were homebrew.  

I think the Tech license worked very well for what it was intended to do, with that exploration.  I knew almost none who just got on the air and talked.  It was about tinkering.  We have lost that.

Ed
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N2EY
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« Reply #5 on: April 02, 2010, 02:24:05 AM »


"Incentive licensing" predated the A-B-C  licenses scheme.  It started with the Amateur Extra First Class license and the Unlimited Radiotelephone endorsement, both of which were grandfathered into Class A.  


Yep - but it wasn't called "incentive licensing" until the 1960s.

A lot of hams, even today, think that it was something new in 1968. Yet the period when Generals and Conditionals had full privileges was less than 16 years.

I still remember getting my first License Manual in 1966 and noticing that four different license classes all had the same privileges. Seemed kind of odd, and there was no explanation.

The Class D license was, AFAIK, the first formal attempt in the USA to have a no-code-test Amateur Radio license. It was strongly supported by the ARRL Board, but hams in general did not like the idea, and it was modified into what became the Technician.

73 de Jim, N2EY
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N2EY
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« Reply #6 on: April 02, 2010, 02:47:24 AM »

the Novice license was good for only one year and could not be renewed, while the Tech license was good for five years and could be renewed.  So we took the Tech test to "hold onto the call sign."  

Yes, that was pretty common.

There were also hams who went to the FCC office and failed the 13 wpm code but then were allowed to take the General written and get a Tech. Then all they had to do was come back and pass the 13 wpm code tests and they had a General. 


By the time I got my Tech license, sometime in the fall of 1956, I think Techs must have been allowed on two meters, but I don't recall for sure.


Techs didn't get any 2 meter privileges until August 21, 1959. Docket 12728 allowed them 145 to 147 MHz, same as Novices had at the time, but without the 75 watt and crystal control limitations of the Novice. Techs didn't get all of 2 meters until the 1970s, and it took two steps - first 147-148, and finally 144-145.


The Tech license was intended to encourage exploration and development above 50 mhz.  That is why it had a sort of technical exam, identical to the General.  It was not a "push to talk" license as it is today.  All of the Techs I knew well into the early 1960s were experimenters.  There was a 220 mhz net in my area and all of the equipment, both transmit and receive, was homebrew.  Some of them used down converters to standard SW receivers, but the converters were homebrew.  

I think the Tech license worked very well for what it was intended to do, with that exploration.  I knew almost none who just got on the air and talked.  It was about tinkering.  We have lost that.

I remember that when repeaters were new to Amateur Radio, Technicians of the time were often involved in putting them on the air. Conversion of surplus land-mobile sets to 6, 2 and 440 were popular ways of building a repeater or a home/mobile station. But eventually that faded away.

I think what happened was this:

First, VHF/UHF rigs specifically made for amateur use appeared in quantity and at low-enough prices that a lot of hams gave up on surplus conversion and homebrewing. This was aided by the drying up of inexpensive surplus sources, and their designs becoming older as the years passed.

The popularity of these small, portable/mobile rigs, coupled with the small size of VHF/UHF antennas and incredible propagation on 6 during sunspot peaks, made 6 and 2 popular with hams whose main interest was operating rather than tinkering. This was particularly true in urban areas and among hams who spent a lot of time in their cars. Repeaters accelerated this trend.

Second, to a lot of hams, the Technician became a sort of step between Novice and General, rather than a special license for a specific purpose.

Third, the reduction of the written test for Technician in 1987 and the dropping of the code test for it in 1991 made the license a popular entry point for new hams.

73 de Jim, N2EY
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AA4HA
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« Reply #7 on: April 04, 2010, 09:39:48 AM »

Whenever possible, I refer to condensers, megacycles and the Class A phone bands.  

Don't forget cats whiskers, Litz wire, Fahenstock clips and the spiderweb coil.

It is sad that so many hams do not know what ladder line is.

I restore "old stuff" but the cutoff dates for me is anything older than the SP-200 or newer than the IC chip.

It's like car maintenance. If you cannot use a timing light, points and plugs for a tuneup it is new-fangled.

Tisha Hayes, AA4HA
"Tetryl-Lead, it's what's for dinner"
« Last Edit: April 04, 2010, 09:42:28 AM by Tisha Hayes » Logged

Ms. Tisha Hayes, AA4HA
Lookout Mountain, Alabama
K6LHA
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Posts: 349




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« Reply #8 on: April 06, 2010, 06:26:58 PM »

AA4HA posted on: April 04, 2010:
 
[N3DF] "Whenever possible, I refer to condensers, megacycles and the Class A phone bands."  

"Don't forget cats whiskers, Litz wire, Fahenstock clips and the spiderweb coil."

Oh, my, the youngsters are speaking again. I 'built' my own 'radio' about 1946, a Philmore Crystal Set kit, had everything you name but a spiderweb coil. Total pre-WWII <elided> cheap junk. Was so useless for AM BC, so fussy and finicky that I didn't bother with any 'radio' thingy until 1947.

Fahnstock clips go back to my late father's birthyear (1900) and are useless even if one has a fine pine  plank instead of a bread board. Litz wire was intended to increase Q of MF-LF inductors through increasing "skin effect" since not many colleges or universities bothered to teach powdered-iron core coils. Those were in use in WWII radios and even in some 1930-design ARC-5 Command Sets. Spiderweb coils were intended to cut down distributed capacity in inductors since nobody seemed to have realized that wiring, tubes, and shield cans for cylindrical coils ALL contributed stray capacitance to parallel-resonant circuits. If one applies some simple, very simple algebra, one can figure out what to do with distributed capacity in a parallel-resonant circuit.

Spiderweb coils don't do anything except make it easy to support the rear-panel loop antenna on an "All-American-Five" AM BC receiver circa 1940. The rear panel was cardboard and punched to create slots to wind the loop antenna. CHEAP. "Loopsticks" of iron-powder or ferrite rods with the Mixer's signal input resonant coil wound on it displaced them. Same price for total parts but the labor to make a loopstick was less than half of the air-core loop.

In 1948 I was seduced by the advertising force of Allied Radio in Chicago and bought a CHEAP metal "coil winder" that could make spiderweb coils of many kinds. Was a waste of teen-ager's money. I tossed it in 1956. Powdered-iron toroidal form coils are the way to go for higher Q with solid wires, much less coupling to other coils.
........................
AA4HA: "It is sad that so many hams do not know what ladder line is."

I think it is SAD that so many actually USE ladder line. "Ladder line" is just another physical form of a balanced transmission line based on old "300 Ohm" TV lead-in using polyethylene to hold the two wires apart. Square holes were punched in the polyethylene between the wires to change the characteristic impedance and force the wires farther apart to allow greater voltage breakdown for mismatched high-power transmitters. TV lead-in was colored brown, supposedly to show that it had some UV protection ingredient in the poly for lasting longer but some makers used plain brown dye with NO UV protection.

If one wants POWER and long lasting use, 600 Ohm parallel-wire balanced line with only spreaders will
handle 40 KW PEP SSB transmitters...which I've tuned back in 1954. Solid wire (steel core, copper outer) supported on 20 to 30 foot high telephone poles. That's the way for both long lasting operation and with minimum loss.
..........................
AA4HA: "I restore "old stuff" but the cutoff dates for me is anything older than the SP-200 or newer than the IC chip."

That's nice. I was designing circuits at work using ICs back in 1962. Still am and they aren't restorations, ICs can be SOC (Systems On a Chip) and SOCs began appearing 40 years ago.

I got some ARC-5 parts in a trade a couple years ago and am beginning a monoband receiver design-construction. Most of the 6-9 MHz interior is now partly gutted and will be rebuilt as a 3.4 to 4.1 MHz single conversion receiver using 7-pin glass tubes for less heat build-up and lower power drain with improved
sensitivity and better Image rejection. The beautiful sheet metal work is kept as is the 3-gang worm-drive tuning capacitor for easy tuning for any mode's carrier. It also uses toroid inductors and 1950 Philips IFTs that went out of production before the 1960s...but my late uncle-in-law designed them into a 3-band low-cost portable consumer-market radio back in 1950 in Sweden. His sold well.

When it comes to electronic structures, I'm not building/designing/collecting museum pieces. FUNCTION
is paramount, stability in environment is right behind that, esthetics will follow as a natural third. I always keep in mind how Bill and Dave would do it. [H-P that is and they started in 1939]
...................
AA4HA: "It's like car maintenance. If you cannot use a timing light, points and plugs for a tuneup it is new-fangled."

Okay, so you don't believe in electrically-powered automobiles. And you didn't spell 'tetraethyl'
properly so natural gas powered is also out too? Diesel? Steam? Why the shift to automobiles? They
have far more electronics IN them than existed when the first ICs were on the market.
================================
"Class D" in amateur radio regulations didn't last long. Class D CB began in 1958 and is still going
with 10 times the number of users than in amateur radio. Class C CB pretty much dropped out because
Part 95 put in Radio Control Radio Service with 100 channels at around 72 MHz. Class A and B CB folded because buyers of that changed over to REAL two-way VHF/UHF radios when the PLMRS made up three Business Bands. Citizens Band Radio Service (Part 95) is still around and rolling on highways and that is the much-longer-lasting "Class D."

RF Microwave components don't look like anything familiar for olde-tyme hammes who've enver gone much
above 20m homebuilt or above 450 MHz with ready-built. I'm familiar with them since the 1950s and all up to about 25 GHz are old friends to me and my hands. But, if you like restoring radios from the 1920s and 1930s, Godspeed. Have a ball. Amateur radio has band allocations on up to the ITU-R allocation limit of 300 GHz. The USA doesn't have any amateur radio band allocations below 550 KHz; other countries do. Below the BC band is simple circuitry spectrum compared to microwaves.

73, Len K6LHA
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N2EY
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« Reply #9 on: April 07, 2010, 10:13:00 AM »


Don't forget cats whiskers, Litz wire, Fahenstock clips and the spiderweb coil.

It is sad that so many hams do not know what ladder line is.


I'll see your cat's whisker, Litz wire, Fahnestock clips and spiderweb coil and raise you a hot-wire RF ammeter, a synchronous condeser and a pair of Tungar bulbs.

What's even sadder is that so many hams think "ladder line" is that brown Twin-Lead stuff with holes punched in it.

73 de Jim, N2EY

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K6LHA
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Posts: 349




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« Reply #10 on: April 09, 2010, 05:00:09 PM »

N2EY posted as if he was born before WWII:

[AA4HA](April 04, 2010): "Don't forget cats whiskers, Litz wire, Fahenstock clips and the spiderweb coil. ... It is sad that so many hams do not know what ladder line is."

"I'll see your cat's whisker, Litz wire, Fahnestock clips and spiderweb coil and raise you a hot-wire RF ammeter, a synchronous condeser and a pair of Tungar bulbs."

I don't know what a "condeser" is but I will presume you mean a GANGED VARIABLE CAPACITOR. GANGED tuning capacitors were known by that name in texts published during 1941 to 1945.

All of the "hot-wire RF ammeters" I've USED since 1953 had THERMOCOUPLE JUNCTIONS in them which had "resistance" from small plates next to thermocouples. In the case of the Collins 40 KW PEP SSB-biased power amplifier the entire RF current meter was insulated/isolated from the 40 KW power amplifier main assembly, one for each line of the BALANCED TRANSMISSION LINE going out to the antenna. For reference see the digitized 1962 military booklet available under:

http://sujan.hallikainen.org/BroadcastHistory/uploads/AlphabetSoup.pdf

or the photo-essay of personal experience 1953-1956 while on military duty at

http://sujan.hallikainen.org/BroadcastHistory/uploads/My3Years.pdf

Both of those are found at the "Saving History from the Dumpster" website "military" grouping of Hal Hallikainen's (WA6FDN) massive collection of communications equipment information website.
...................
N2EY: "What's even sadder is that so many hams think "ladder line" is that brown Twin-Lead stuff with holes punched in it."

This USA amateur radio license, always licensed as an Amateur Extra class refers to ALL balanced, parallel transmission lines as PARALLEL WIRE TRANSMISSION LINES. Physical form can be "open" parallel lines (air dielectric) with "spreaders" (colloquial name) of narrow insulators keeping the spacing betweem wires fairly constant along its length, typically 600 Ohms characteristic impedance as used in higher-power communications systems; a continuous ribbon of polyethylene insulation between two flexible wires embedded in that polymer ribbon's edges, typically a brown color to denote its use as TV receiving antenna "lead-in" and desceibed as "twin-lead" colloquially; a variation of "twin-lead" by (usually) square holes punched in the polyethylene ribbon support. During the 1950s a variation of the cheap "twin-lead" was available in an approximate 75 Ohm characteristic impedance intended for simple FM audio broadcast receiving antennas. That 75 Ohm twin-lead did not receive buyers' support since many home entertainment receiving antennas were designed for wide-band operation and could cover the FM BC band of 88 to 108 MHz...and a specific full-azimuth pattern "turnstyle" (colloquial) crossed folded dipole FM antenna used 300 Ohm "twin-lead" feedline.

BTW: The physical color of "twin-lead" wasn't always brown. That color was standardized as being the cheapest for the polymer and many brand-name "twin-lead" types had NO UV protection, plasticized early, and needed many more TV service calls than true UV-protection "twin-lead."

ABTW: Early Boonton Q-Meters used thermocouple type RF current meters at low RF power levels. The 260A Q-Meter (good repair/calibration page at www.qsl.net/k5bcq) is an example. So did the VHF-UHF model Q-Meter that I own. Thermocouple RF current meters were the first truly wideband devices for 'radio' back before WWII. These were TRUE RMS current measuring devices converting heat to a DC voltage output that could indicate on a conventional DC current meter. Several semiconductor makers had specific ICs to do the same thing for very low power, heat to several transistor stages to produce a voltage, same as a thermoelectric function, all to indicate RF power.

YABTW: Your 'sensational' "Southgate Type 7" is pictured on Kees Talen's (K5BCQ) website in picture  
form (B&W overlarge size due to too fine pixels) same as you've spread to other old-ham websites. However none of those include SCHEMATICS of those wonders 'designed' around 1970 (40 years ago). Why NO schematics? Do you think someone might recognize schematics way too close the "HBR series" that appeared for years in QST? Over a dozen different version of "HBR" models over a decade plus.

K6LHA
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