MAXIMIZING SENSITIVITY / FINALE - 1953 VACUUM TUBE CAR RADIO Part 6 - CHEVY MODEL 986668 [4K]

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  • Опубліковано 22 гру 2024

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  • @jimnewman5596
    @jimnewman5596 Рік тому +1

    I really enjoyed this video series on the car radio. I learned some good tips on car radio repair. The radio sounds great.

    • @PracticallyFixed
      @PracticallyFixed  Рік тому +1

      Thanks Jim, I enjoyed having you and the other viewers along, especially those to say hello and comment. This was an enjoyable project for me as well. The last project that was part of the 3 challenges sent to me by the same fellow is not something I have seen anyone else do. Hope you find it interesting too; parts are enlightening some may say.

  • @janbill79
    @janbill79 Рік тому +1

    Yes I agree, really good informative series. Very detailed for sure. I should have a much easier fun time getting my 6 volt from 1948. It just mine doesn't have the rectifier tube because the points have two sets of pointsin the vibrator, then I gues it's called synchronous type

  • @hestheMaster
    @hestheMaster Рік тому +1

    Never heard of UF4007 diodes in the Silicon diode world. Silly me. Their features of high surge current capability and
    high reliabilty as a replacement diode for lets say a Selenium rectifier in a tube set in the home makes me think I could
    use them instead , well if I run out of the 1N4007 ones I have. I'm glad you found that info on the condenser used in the
    auto generator and the rest. I knew it was important to design noise suppression for a tube radio in cars back then. We
    often forget why certain electrical components were put in cars in the first place. Like tire static? Who knew. One thing
    I might ask if after the car owner puts the radio back in his car we can see a video on how well it receives stations after
    all this work you put into it PF , like Doug's post below where he mentions that. Great series man! Steve

    • @PracticallyFixed
      @PracticallyFixed  Рік тому +1

      Thank you Steve. Yes I hope he is willing and sends a video when it is in and he is ready to show it. I know he is still working on the dash, instruments and interior so we can't rush him. He has owned this car for over 40 years so he owns the timetable. He is in an even more rural area than I and is surrounded by hills and he told me his reception for any radio is limited. I am hoping he will be able to get some evening and night DX; I sent the call sign and frequencies of several FCC Clear Channel Class A stations in his region of the country so hopefully he will be able to get some of them when the car is out of the garage. I had not heard of the UF (Ultra-Fast) version of the venerable 1N4007 either so the credit definitely goes to Jeff Angus at the Radio Museum forum who posted the info which I showed. I will be using them too. Thanks for your help as well.

  • @DERB_Seymour_Indiana
    @DERB_Seymour_Indiana Рік тому +1

    Nice wrap up on the radio PF. Wow, it does seem to be very receptive. LOL Would be interesting to know how well it performs back in the car if that is a possibillity? The one in my '61 Buick is a tube type Delco radio and it would be neat to see the circuitry differences of almost 10 years would be. I think GM switched to solid state radios in '62 or '63. I tested mine in the car back when I got the car about 13 years ago, but have never had it out on the bench to have a look at it. Might have to do that one day. :)

    • @PracticallyFixed
      @PracticallyFixed  Рік тому

      Hi Doug and thanks. The car restoration is on-going as elements of the interior are still being received and the radio will be eventually installed. That would be interesting to see the differences from a '61 Delco. Hope you share the adventure if you look into it. Thanks again.

    • @PracticallyFixed
      @PracticallyFixed  Рік тому

      Doug, I found a schematic for a '61 Buick radio online. It was a tube radio but had an output transistor. The tubes ran on just under 12V so there was no power transformer. It would be interesting to see if you decide to take a look at it.

    • @DERB_Seymour_Indiana
      @DERB_Seymour_Indiana Рік тому

      @@PracticallyFixed So it is quite different than the one you have. I might pop it out when I go to put those new 6X9 speakers in the back. :)

    • @PracticallyFixed
      @PracticallyFixed  Рік тому

      Here is the link to a schematic I found which might be for your radio. If you look at the URL looks like the Shop Manual is there for the car as well if you need it. Thanks
      Have to change it up some some so YT doesn't block a link: You know what to do with the 'slash's and 'dot's. The percents are as they are in the url: buick dot oldcarmanualproject dot com slash manuals slash1961slash 1961%20Buick%20Special%20Shop%20Manual slash 11-Radio%20Heater%20AC slash n_P0007 dot jpg

    • @DERB_Seymour_Indiana
      @DERB_Seymour_Indiana Рік тому +2

      @@PracticallyFixed I appreciate all the trouble, but actually one of the first things I bought when I got the car about 13 years ago was a PDF copy of the SM on CD. I do have the schematic for my radio and it looks like it has a transistor for the IF amp as well as the audio output. A true hybrid for sure. :)

  • @peterlidberg2462
    @peterlidberg2462 Рік тому +1

    Very interesting. But are you not you getting somewhat higher voltage readings using the modern digital voltmeters compared to using the old style analogue turning coil instruments that were used when the car radio was new?

    • @PracticallyFixed
      @PracticallyFixed  Рік тому +1

      Hello and thanks for watching, and the comment. That is an interesting point and is something that I did not focus on at the time, but your comment sent me back to the schematics. There were 4 schematics I used in this series (Beitmans, Sams, United Auto, and the Chevy Shop Manual) and I did not realize the differences they contained until I noticed one of the them had the AVC resistor values this set contained, versus the other schematics which had different values. While I frequently used one schematic which was technically an older revision (Beitmans), I thought it showed up better in the video. However when I got around to doing the final voltage checks to test out how the solid state rectifier was doing, I used the correct one (Chevy) with the correct AVC resistor values for this set.
      Looking at the detailed notes of these schematics, the one from Beitmans called out using a 1,000 ohm per volt VOM. I thought "oh, that is a big difference to the DMM" (the manual for the Fluke 27/FM gives the nominal input impedance as 10Meg ohms). The Sams and the United Auto schematics call out 20,000 ohm per volt VOM, much better. However I just noticed the schematic which I used for the voltage check, from the Chevy manual, called out using a VTVM, which as you know is very high impedance compared to the 1,000 ohm per volt VOM (and were also around when this radio was being made).
      How much difference that would make will vary with the circuit, but if one is trying to be precise it is wise to keep your point in mind. I normally do not sweat that degree of precision in tube gear from the 50s but was giving it a lot of attention in this case to be sure the diodes with the resistors were working ok.
      So in general you are quite right, and some of the schematics I showed did indeed mention VOMs including one at 1,000 ohm per volt, but I was using one at the final check which happened to call out a VTVM, so while I was not careful about that..."I think I got away with it!" (- Basil Fawlty) I won't dust off my old VOM just yet anyway however, I like the autoranging DMM so much more than the old days which I remember well, just need to keep expectations when comparing measurements in check. Thanks for the excellent observation. [edit: corrected impedance for Fluke 27/FM]