75A-4 mods: 1s that work well

Discussion in '"Boat Anchor" & Classic Equipment' started by W5INC, Jan 25, 2015.

Thread Status:
Not open for further replies.
ad: L-HROutlet
ad: l-rl
ad: L-MFJ
ad: K5AB-Elect-1
ad: Left-2
ad: MessiPaoloni-1
ad: Subscribe
ad: Left-3
  1. KA9JLM

    KA9JLM Ham Member QRZ Page

    The SC-101 would be nice to add to a collection.

    I would guess not many of them were made.
     
  2. W5INC

    W5INC XML Subscriber QRZ Page


    Smart idea there Mr. Glenn as you can accessory features down the road from the time you bought the speaker. Almost looks like the same type of clock that was put in Heathkit station controls back in the day. Art deco styling at it's AR best, I reckon. :)
     
  3. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    That is the old Tymeter Numechron "digital" clock. Motorola used thousands of those clocks in various base stations and remote consoles in the 1950s and 1960s. Heath did use them in the SB-630.

    tymeter clock.jpg

    Glen, K9STH
     
  4. KA9JLM

    KA9JLM Ham Member QRZ Page


    Are them the ones that were hard to keep the digits to line up ?
     
  5. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

  6. KA9JLM

    KA9JLM Ham Member QRZ Page


    Nice.

    Who is that young man in the picture ?
     
  7. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    I wonder what happened to him as well! :rolleyes:

    Actually, that was when I weighed the most, about 185-pounds. Since then, I am down over 15-pounds and my hair has gone gray. Otherwise, still as handsome! :p

    Now, waiting for ERV's comments!

    Glen, K9STH
     
  8. W5INC

    W5INC XML Subscriber QRZ Page


    Nothing wrong with growing old there Mr. Glenn, it sure does beat the alternative, even with the grey hair.

    Getting to the noise blanker mod on SB #2. Collins added 2 @ 510 mmf capacitor into the circuit, so I ordered 2 @ 5100 pf caps. Hopefully I converted these older numbers of capacitance to the newer standard now used correctly. I am hoping it is, as these 2 caps were over 8.00 a piece. No telling what the parts cost would be today to build 1 of these 75A-4s from scratch today. :) Any ideas from the folks a lot more versed in the price point of today's components? :)
     
  9. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    Unfortunately, a 510 mmf capacitor is the same as a 510 pf capacitor!

    Glen, K9STH
     
  10. W5INC

    W5INC XML Subscriber QRZ Page


    I had the salesperson at Mouser connect me with a tech to double check my conversion and he did agree with me. :mad: Got the pieces in my hand a few minutes ago, I guess I will have to call Mouser back up and exchange them. Was wanting to finish up this mod but I guess it will wait till I get the right parts. I will put the juice to the 75A-4 tonight for the 1st time in what might be a few years. I have all of the tubes needed now, all caps changed out and just got this piece in today at the same time the parts showed up from Mouser. The 270G-1 is in good shape and looks to have the original Jensen speaker still installed in it. Hopefully some kind of noise will come out of the box, when the switch is thrown. :)

    270G-1.jpg
     
Thread Status:
Not open for further replies.

Share This Page