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Grounding the Grids vs. Cap/RFC Grounding

Discussion in 'Amateur Radio Amplifiers' started by W4LAC, Jun 13, 2019.

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  1. KM1H

    KM1H Ham Member QRZ Page

    The AL-80B uses a #16 wire for grounding the 3 socket pins. I dont remember if they are all daisy chained and to a common ground or individually grounded; its been awhile since I looked that close to the bottom of the socket.

    They are an easy and very stable conversion to 6M.

    Here is one worthwhile mod
    http://www.w1aex.com/al80b/al80b.html

    Carl
     
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  2. K9AXN

    K9AXN Premium Subscriber QRZ Page

     
  3. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    No, silly! :p

    Cricket
    (click me)

    The World Cup Match was today.

    England WON!

    I was cutting records all day...

    Rug Rats:

    xmas pic.jpg

    Cricket:

    maxresdefault.jpg
     
    Last edited: Jul 15, 2019
    K9AXN, KM1H and N2EY like this.
  4. W1QJ

    W1QJ Ham Member QRZ Page

     
    KD2ACO, KM1H, W2VW and 2 others like this.
  5. KM1H

    KM1H Ham Member QRZ Page

    Thanks for that great post and updates Lou. I wonder who was responsible for that new socket?

    Apparently Ameritron kept quiet about the problems and tried different things to make their 3-500 amps stable. That socket is Part # 50-0080-5 in the 2019 MFJ catalog and $32.20 plus shipping and a pair might be an interesting experiment in a SB-220.
     
    KD2ACO likes this.
  6. KM1H

    KM1H Ham Member QRZ Page


    YAWNo_O Sorry but I cant get excited over most sports, I lean toward NASCAR for starters along with European Road Races for many years.

    Adorable/Cute Rug Rats (take your pick) BTW:D

    Carl
     
  7. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    I'm not a sportster either, but England comes to a halt for the Cricket World Cup... especially if they have a dog in that fight.
    ... must have been the mailman... :oops::p

    Anyone have a SB-220 coil and/or a couple of suppressors laying around for Jeremy to hook up to his VNA?
    I don't see any contact info for him here...
     
  8. KM1H

    KM1H Ham Member QRZ Page


    I have MANY l RL "pulls" thrown in a box available, Throwing things away is a sure indication they will be needed as taught to me by Vic Penney at National. No NOS 47 Ohm 2W carbons left here however but 3-5W MOX and Ohmite OY should be off the shelf in the UK. Jeremy seems to keep any personal data very private.

    Just a thought but lower value carbons may have drifted up to within 10% tolerance for 47's which should be fine for microwatt VNA power.
     
  9. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    I only have 56 ohm Allen-Bradley 2 watters here. I use 47 OYs also now (at your suggestion years ago) and don’t bother looking for NOS carbon comps.
     
  10. KM1H

    KM1H Ham Member QRZ Page

    So now you are the expert on every product that used the 8122 and all its variants? Please list them.

    R-314 is not on your Edebris schematic so I had to go to the remote mounted PS and found it there as R-312, thanks for the wrong info. Conventional wisdom says that resistor should be close to the RF choke, and out in the open as it is in the NCL-2000. OTOH high RF power was new to Halli (except for the old HT-4/BC-610 days of WW2 ) so they can be excused the lack of knowledge but that doesnt excuse it now by someone that actually has the self claimed in depth experience and knowledge.....:rolleyes::eek:

    The NCL-2000 is an amplifier, not a transmitter, please learn the difference.
    I saw that so called fix kluge article and quickly ignored it as desperation based on little facts. I saw no need to inform you either based upon past hostile experience. The amp design had nothing to do with bandswitch problems. The 3 I have here all have the original switch and are in use, one is even dedicated to AM at up to 1200W PEP thanks to plenty of air from the blower. So much for switch problems.

    The REAL PROBLEM was the solder used in assembly. Under RF loading it soon crystallized and presented a resistive and overheated connection thruout the output circuit, it wasnt just the switch contacts.. Since I was the only person in the Service Dept working on them I found the problem. Others in that IBEW Union Shop refused to work around HV and since I already had plenty of HV experience at home and in the USN going back to 1957, I readily volunteered....screw the union. The fix was to remove all solder (solder sucker, etc) and reflow a good quality Sn-Pb rosin core solder. I dont know what National Radio was using but likely the same going back to the 20's or 30's as that division had no high power RF experience until the NCL-2000.

    I have also seen crystallized solder in other amps, such as Heathkits but being kits I have no idea what was used by the builders.

    The joint heating also discolored and loosened the nuts on the Tune cap as well as overheated the fiber insulators between the two cap sections. The Service Dept provided solder, hardware, ceramic insulators, and instructions written by yours truly.

    I suggest that you stop your years long attempt to discredit National and stick to what you actually might know..... a small few Hallicrafters models.

    Huh....did you loose some gray matter here and mix me up with someone else? Or just trying to cause more trouble?

    Speak for yourself, I dont need tranks. My doctor is always amazed at my young mans blood pressure, heart rate, ideal weight, daily exercise program, and general good mood. Posting on forums helps:p
     

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