ad: w5yi

AL 811H intermittant.

Discussion in 'Amateur Radio Amplifiers' started by K5WP, Dec 22, 2010.

Thread Status:
Not open for further replies.
ad: l-rl
ad: abrind-2
ad: l-BCInc
ad: L-MFJ
ad: Subscribe
ad: Left-3
ad: Left-2
  1. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I just saw this and wouldn't comment, since Tom is the designer and would have more insight than I could.

    However the AL-811H is pretty popular, I must work a dozen guys a week using them, and most have no problems except the ratty 811As which I guess are getting rattier.

    I know one local found a stash of NOS RCA JAN-811As made in the late 1960s and he uses only those -- with no issues. I think when RCA stopped making them, the problems began.;)
  2. N4AUD

    N4AUD Ham Member QRZ Page

    There's some obvious sabotage in this thread and it doesn't take Sherlock Holmes to see it. It's a shame too because there is an obvious opportunity to learn here. I've been a member here on QRZ for years and hope I don't get banned for stating the obvious but the designer of the amp isn't the trouble maker. :mad:
  3. K9STH

    K9STH Ham Member QRZ Page

    There is a difference between the design of something and the production of that same something. Also, you have to consider that Ameritron was purchased by mfj a while back and then look at mfj's track record in quality assurance.

    Glen, K9STH
  4. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    IMO, Ameritron quality actually improved under MFJ ownership! (No kidding -- they weren't so great initially.)

    My AL-80B is now 10 years old, and was build under MFJ's ownership. There was an unsoldered wire on the STBY/OPR switch which rendered the amp nonfunctional the moment it was turned on.:eek: However, other than the nuisance of removing more than a dozen screws to take the cover back off (darn), this was really easy to fix (30 seconds) and the amp's worked perfectly ever since.

    Since I had the cover open anyway, while I was in there I added some more AC line filtering than it had because that was easy to do.

    But it's a fine amp. First tube lasted 7 years of very frequent operation, second tube is still in there and doing fine. Neither was an Eimac, as they stopped making the 3-500Z more than ten years ago. Perfectly satisfied with it.
  5. W8JI

    W8JI Ham Member QRZ Page

    The 811 and AL80B was never produced by anyone except Ameritron under ownership of MFJ, so it would be very difficult to equate any change in ownership with QC of those amps. :)

    I'll ask about the rocker switches.

    I don't worry about any of this or take any offense personally. I'm not an amplifier, and I'm not fractal either. Things aren't really people, and don't make us less or more. :)

    73 Tom
  6. W1YW

    W1YW Ham Member QRZ Page


    It has been suggested to me that I have the AL-811H taken apart and re-soldered, because of poor QC on hand soldered connections at the factory.

    I may be able to have an intern do that.

    So where are the likely weak points--hand soldering; heat dissipating; etc.

    What is the best way to get at the rectifier?

    What is the best way to get at the pins/socket wiring?

    Chip W1YW
  7. W1YW

    W1YW Ham Member QRZ Page

    Hi Audie,

    I would very much like to learn how to get good use of the money I slapped down by buying this AL-811H amplifier.

    The best advice, proffered by WA6MHZ, is to break down the unit and re-solder the hand soldered points.

    Do you have any helpful suggestions?

    Chip W1YW
  8. W1YW

    W1YW Ham Member QRZ Page

    Hi Glen,

    What is that distinction, please.

    All the RF designers I work with are required to specify specific parts and alternatives--as part numbers--before something goes to production. It has become the function of the designer. Its part of the design.

    Chip W1YW
    Last edited: Jan 16, 2011
  9. K9STH

    K9STH Ham Member QRZ Page


    You are working in a different work environment. Unfortunately, there are companies that contract the original design of a unit outside of the company. Since there are no mil spec requirements production people often make changes in the components actually used to manufacture the item based on the function of the component (including things like the value - i.e. 500 pf variable capacitor) rather than using a specific component manufactured by a specific company that may have been used by the person who designed the unit. Again, unfortunately, these component changes are often made based on the cost of the component rather than the absolute quality of the component. Many times the changes are dictated by someone with no real technical knowledge and are dictated with the "bottom line" in mind.

    We are basically talking semantics. What I am calling "production changes" you are calling "design changes". To me, a design change involves things like altering the particular value of the component rather than using a lower priced/lower quality component from a different supplier. Since in the consumer world there are no mil spec requirements, companies often make decisions based solely on economics without taking into consideration things like long term reliability. I agree that reliability should be considered. But, those considerations are often lost in the rush to optimize profit.

    Glen, K9STH
  10. W1YW

    W1YW Ham Member QRZ Page


    I would be much obliged if you used my name. Thanks.

    Sure, we agree, on concept.

    But it is unlikely to be a tube issue (for example)--as I mentioned, I already changed them out and the unit still gives a death rattle and pulls the fuse.

    Chip W1YW
Thread Status:
Not open for further replies.

Share This Page