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Transmitter tubes of recent production are prone to easily break, aren't they?

Discussion in 'Amateur Radio Amplifiers' started by JL1DCA, Apr 28, 2017.

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  1. JL1DCA

    JL1DCA Premium Subscriber QRZ Page

    Chris, Have you yet got in Tokyo?
    We Japanese are having a series of holidays, which is arranged in a comfortable spring time and called Golden Week, till next Sunday.
    I was wondering if sushi was OK for you, as I know Obama doesn't like it. Shibuya this week will be having lots of visitors from abroad while Japanese residents in Tokyo leave there for going back to their native lands or for leisure. I'm a Tokyoite.

    I could use and install a step-up transformer for driving the fans by 117VAC instead of original 100VAC. The fans may heat but can cool themselves as much more.
    Dan Suzuki Jl1DCA
     
    Last edited: May 1, 2017
    AF6LJ likes this.
  2. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    I love Japanese food! It will be fun to visit Tokyo. I'll be very busy at NHK but will send a text as soon as I figure out what is going on.

    Shibuya looks great in pictures and is not too far from your QTH. That is where the studios are.
     
    Last edited: May 1, 2017
  3. JL1DCA

    JL1DCA Premium Subscriber QRZ Page

    I recall NHK (National broadcast network) was going to build a new office building a quarter hour's walk from Shibuya Sta.
    I wonder if its construction has been completed and they are setting up equipment inside.

    I have had AC voltage to drive the fans raised to 110VAC from the original 100VAC.
    Fan noise became louder but it's not as much as to be issues.
    I'm a little afraid that they may be overdriven and heat up, surpassing the increased self-cooling taking effect. My Amerian friends say Tokyo is much like NYC.

    Taihei Suzuki
     
    Last edited: May 1, 2017
  4. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    It's even MORE crowded here! :p
    Must sleep, will text tomorrow.
     
    JL1DCA and AF6LJ like this.
  5. G3YRO

    G3YRO Ham Member QRZ Page

    How long did you have the Amplifier transmitting continuous full power then?

    I certainly never ran mine at full power for more than 2 or 3 seconds at a time.

    The internal fans, if regularly serviced, are OK for normal QSOs . . . but if you are operating continuously, like in a contest, the whole case would get very hot!

    So what I would do in contests is place a 5 inch fan on top of the PA compartment, sucking all the hot air out. This would stop it getting hot.

    And as others have said, I have found the new China-made 572Bs as good as the American Cetron ones. Although I always bought mine direct from China for less than half the price!

    Well Yaesu have clamps around the base of both 572Bs, to support them.

    Roger G3YRO
     
  6. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    Thanks Roger. Can you observe the plate color while the amp is running (are there vent holes in a place where you can see the valves)?
     
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  7. JL1DCA

    JL1DCA Premium Subscriber QRZ Page

    Hello, Roger.

    Shuguang(曙光電子)572B has 190 of the amplification factor contrary to 170 of 572B/T160L(
    Cetron and Taylor).
    It causes shortcoming of Ip when it is used for /T160L even if the variable wound resistor is set to the minimum.
    The valves cannot be observed from outside while running.
    Its users' manulal tells tuning must be done within five seconds at a time and 5~10minutes of an interval is required before resumption of
    tuning. I made a contenious carrier transmission at the full power over 15 seconds or even longer.

    Taihei Suzuki JL1DCA
     
    Last edited: May 2, 2017
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  8. JL1DCA

    JL1DCA Premium Subscriber QRZ Page

    Chris, what do you say to going to Akihabara later on after we meet at Shibuya, probably with an appointment for another day

    There will be of much more fun for you than Shibuya.

    ~ users' manulal tells tuning must be done within five seconds at a time and 5~10 seconds of an interval is required ~

    Taihei
     
    Last edited: May 2, 2017
  9. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    There is a pair of genuine T160L tubes here. Any answers about this amplifier I have to leave to others here with experience.

    The work here is intense for another day as I need to make sure it can be finished. PM sent.
     
  10. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    The message came in that your amp is going to be ok!
    That's good news.
    I'm thinking about Roger's post and it seems to me that a helper fan on top of the chassis may be a good idea if you want to run continuous carrier modes. Maybe 125-150 watts with a good fan.

    I would be worried with much more continuous power than that. :)

    Email me if you are ever in NYC. There's always good music and food around here.
     
    Last edited: May 7, 2017

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