History of Single Sideband in Amateur Radio

Discussion in 'Ham Radio Discussions' started by AF4RK, Aug 10, 2017.

ad: L-HROutlet
ad: l-rl
ad: l-gcopper
ad: Subscribe
ad: L-rfparts
  1. N2EY

    N2EY Ham Member QRZ Page


    All true - I agree 100%. And there was used equipment too.

    What many hams did in those days was to start with a basic station, adding and upgrading along the way. Manufactured ham gear had decent trade-in value; well-built kits as well. Surplus somewhat less, and homebrew least of all.

    All one has to do is to look up rig prices in old magazines and catalogs, and apply the inflation factors from an online calculator, such as the Westegg inflation calculator:

    https://westegg.com/inflation/

    For example, a Drake TR-3 cost $550 in 1963. Which inflates to $4381 in today's money - and that's without power supply, speaker, mike or key! Yet, the TR-3 was considered a "bargain" compared with the Collins KWM-2, which cost twice as much.

    73 de Jim, N2EY
     
    N2SR likes this.
  2. K9STH

    K9STH Ham Member QRZ Page

    The https://westegg.com/inflation/ URL is the inflation calculator that I use. Comparing the original cost of even the most simple transmitter, or receiver, in comparison to what they would cost today, is an eye opening experience. Then, taking the cost of "modern" equipment in the reverse is even more eye opening!

    For example, the Heath AT-1 transmitter kit sold for $29.50 in 1953. That equates to $268.87 in today's purchasing power! That was for a CW only transmitter that put out 25-watts on a really good day and covered 80, 40, 20, 15, and 10-meter bands!

    Now, compare that with an Alinco DX-SR9T that HRO has for $565.95. Adjusted for inflation, that amount would be $62.10 in 1953. But, even though the Alinco unit would have cost a little over twice the amount of the AT-1, the DX-SR9T covers the 160, 80, 60, 40, 20, 17, 15, 12, and 10-meter bands. It has a receiver, can operate on SSB, CW, AM, FM, and with optional source, data, and puts out 100-watts!

    There are even less expensive transceivers that are, occasionally, "on sale" by several amateur radio distributors. The performance of those units are light years ahead of the AT-1.

    SSB has come a LONG ways from the late 1940s and early 1950s. In the "goode olde dayes" it was a novelty and nowadays SSB is the "standard" for amateur radio phone communications. Will digital voice replace SSB? I have no idea! But, at least for VHF / UHF, data voice has made a foothold.

    Glen, K9STH
     
    AF6LJ and N2EY like this.
  3. W2AI

    W2AI Ham Member QRZ Page

    Those were the days before credit cards, credit bureaus and credit scores. To get a "loan" or to buy "on time" from AES; they wanted to know the following: Your job and salary? How long did you work there? Does your spouse work? her salary? Do you own or rent? Your overall monthly expenses? Your employer's name and address. Any outstanding loans? AES allowed up to 36 months to pay.
     
    AF6LJ likes this.
  4. N2EY

    N2EY Ham Member QRZ Page

    There is a long history of "buying on time" in the USA. All credit cards did was to consolidate a pile of merchant-specific charge cards into one.

    There was one other big difference, though......

    In those days (before the early 1980s), if you itemized deductions on your income tax, you could deduct ALL interest paid, not just home mortgage interest. Car loans, student loans, store credit cards, etc. - all of the interst you paid was tax-deductible. What this did was to reduce the effective interest rate you paid - an incentive to "buy on time".

    73 de Jim, N2EY
     
    WU8Y and N2SR like this.
  5. N2EY

    N2EY Ham Member QRZ Page


    25 watts output from an AT-1? Nope.

    In QST for October, 1955, W1ICP described extensive modifications for the AT-1. But before the mods were started, he measured the DC plate input and the RF output of the AT-1 into a 50 ohm dummy load.

    What W1ICP found was amazing. The actual DC input power to the plate of the 6L6 varied from 26 to 34 watts (he measured plate current, not cathode current) and the RF output varied from 5 to 9 watts.

    AT1Power.jpg

    The AT-1 was a terrible design in its time, and is even worse today.

    73 de Jim, N2EY

     
    Last edited: Aug 13, 2017
    N2SR likes this.
  6. SM0AOM

    SM0AOM Ham Member QRZ Page

    Some well-heeled individuals commissioned the design and building of their transmitters to "pro:s".

    Here is an example of the CW/AM transmitter for 500 W+ with parallel 813:s modulated by p-p 813:s that SM5RM (SK)
    let SM5LI (SK) build in the mid-50¨s, for a component cost of about 4500 SEK, around 3 - 4 average monthly wages.

    When SSB came in the mid-60's, SM5RM sold the transmitter and bought an S-line, complete with 30S-1.

    73/
    Karl-Arne
    SM0AOM

    sm2azg_am-trx.jpg
     
    WA3VJB, AF6LJ and N2EY like this.
  7. N2EY

    N2EY Ham Member QRZ Page

    Nice job!

    The VFO appears to be the PTO unit sold by Collins. (Collins sold a version of their PTO, with dial, to hams for homebrewing purposes).

    In the USA, a pair of 813s would often be pushed to a full kilowatt DC input, even on AM. They were available rather inexpensively here, in WW2 surplus.

    Any pictures of the inside of the unit?

    ---

    I have a copy of the RSGB Handbook from the 1960s. In the back is an ad section, and one could buy predrilled and bent metalwork for some of the projects, as well as fully-built=and-aligned front end assemblies for some of the receiver projects. So there was a building activity somewhere between homebrew and kit assembly.

    73 de Jim, N2EY
     
    Last edited: Aug 13, 2017
    N2SR likes this.
  8. AF6LJ

    AF6LJ Premium Subscriber QRZ Page

    I think I am in LOVE :)
     
  9. K9STH

    K9STH Ham Member QRZ Page

    The PTO appears to be the Collins 70E-8A. The original PTO that Collins sold for use as a VFO had a weird fan type of dial with a very long pointer for the MHz scale and a metal disc for the kHz scale. Somewhere, in my attic, I think I still have one of these original PTO dial assemblies. However, I did convert the PTO to the newer style dial. The PTO is visible in the first photo at

    http://nebula.wsimg.com/dc1263b048e...50C433DB440D6B60D&disposition=0&alloworigin=1

    in the lower left-hand side just below the Collins 75A-1 receiver (serial number 4).

    Collins then redesigned the PTO dial assembly and went to the slide rule for the MHz scale and a plastic dial for the kHz scale. They had a kit to replace the old style dial with the new one.

    Glen, K9STH
     
    N2EY likes this.
  10. AF4RK

    AF4RK Premium Subscriber QRZ Page

    I found the complete collection of CQ magazine from 1945 on line (https://hamcall.net/cq). I came across an article where the author claims to be using 3999.5 kHz LSB to avoid the"AMers". Pre-War SSB rigs were influenced by the W6DEI design using triple conversion and LSB. It's likely that the 75 meter LSB convention began before the war. But that doesn't explain USB on 20. Well half a loaf is better than none. Case closed. I see this thread degenerated into chaos very quickly but there were some nice pictures of old radios. Unfortunately, I didn't hear from anyone who was there in 1945 with a rational explanation. There were a lot of irrational explanations, though. W1LSB (great call!) had the best comment and I found him through google. Nothing to see here folks, time to go home and cook your pot roast.
     

Share This Page