Hallicrafters SR-2000. Got one but also got issues

Discussion in '"Boat Anchor" & Classic Equipment' started by KB1SLN, Mar 26, 2018.

ad: L-HROutlet
ad: l-rl
ad: Subscribe
ad: L-MFJ
ad: l-assoc
ad: Left-3
ad: MessiPaoloni-1
ad: Left-2
ad: l-BCInc
  1. KB1SLN

    KB1SLN Ham Member QRZ Page

    A couple of weeks ago I managed to acquire a Hallicrafters SR-2000 with the P-2000 power supply for a really good deal. After a full recap of all the electrolytics in the power supply and cleaning of 50 years of oxidation on contacts, dirt and general grime, and replacement of one bad 7059 tube, the radio was brought to life.

    At this point it is receiving very well on all bands that have had activity. Due to this past weekends contest I was able to hear a ton on 15, 20, 40 and 80 and I must say I am impressed with the receive on this guy.

    Here is where I need some assistance...

    1) Power supply makes a horrible buzzing when the HV is engaged. Good news is that the HV does engage and I get 1700 V but the buzzing makes the windows shake. Assuming its a choke issue in the power supply but how do I diagnose which one and what are my options for the one that turns out to be bad.

    2) During my investigation while I was cleaning this radio up and getting it ready to go, I saw that some previous person had removed the cap connections from the 8122 tubes. Interesting I thought. Had no idea why they did it so I reconnected them.

    When I follow the tune-up process from the manual to the letter as soon as I switch over to "MOX", the HV instantly switches off. So, were the caps disconnected because the 8122's were NG, were they disconnected because something else in FUBAR in the transmit section? Where do I begin troubleshooting this and is there a source for matched 8122's should mine be NG. I have no way to test the 8122's

    3) S meter/screen ma meter is not working. When powered on the needle goes to about the "5" and sits there. On a really strong signal it will move very slightly. Also If i change the switch to Screen MA it will peg the needle below zero and it won't come back up till I power off and turn back on. Where do I begin on this one?

    I will post some videos and pictures soon.
     
  2. KB1SLN

    KB1SLN Ham Member QRZ Page

    First pic
     

    Attached Files:

  3. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    The P-2000 doesn't have any chokes: It has two transformers, one HV (plate and screen) and one LV (everything else).

    Do you have the service manual?
     
  4. KB1SLN

    KB1SLN Ham Member QRZ Page

    I do and the schematic and parts list clearly show L301, 2 and 3 as a screen choke and two filter chokes. So is the schematic and parts list not accurate in its description?
     
  5. K9AXN

    K9AXN Ham Member QRZ Page

    The schematic is correct as you see it; a screen choke and two LV chokes.

    Send the serial number and close ups of the under and over chassis of the SR-2000 along with a close up of the final compartment and band switch.

    That radio is a fine instrument when working properly. I would strongly suggest recapping the P2000 and SR-2000 before operating it.

    The buzzing from the power supply is probably from a relay however the disconnected plate caps are troubling. If the last person to use it disconnected them then engaged the HV and keyed to transmit, he will have heard the notorious plink of death as the screens self destructed. If the screens were destroyed they may be shorted causing the choke to chatter.

    The pre-production SR-2000 used a separate two wire plate and screen connection; then found that folks would remove the plate connection without removing the screen wire and engage the HV destroying the screens. The fix was a single connector with both wires.

    I have a stock of matched 8122's. I can test the 8122's for function and match. Measure the resistance between pins for shorts and let me know how they look --- any dents throw it away.

    As for the S-Meter, there's a procedure in the manual to adjust it or simply set the AGC pot fully off, use the Zero pot to set the meter to zero, then adjust the AGC pot to just move the needle off zero.

    There are numerous shortcuts to make the radio right. All of the transmit circuits can be tested without HV engaged. There is a good deal of info on www.k9axn.com

    If your interested in pursuing a complete restore we can help you out but I've retired from active restoration.

    Kindest regards Jim K9AXN
     
    Last edited: Mar 26, 2018
    AF7XT and N2EY like this.
  6. KB1SLN

    KB1SLN Ham Member QRZ Page

    Thanks for the reply Jim. I will work on the pictures and get them up this evening.

    I don’t know the history on this radio as I came in to possession by just a random stroke of luck so not sure what issues it may have had and the guy I got it from never powered it up in the 15 years he had it.

    The very first thing I did was a full recap of the power supply including all 8 of the 100 mfd cans and the assorted electrolytics underneath before I ever powered it up.

    I have spent several hours on your site and look forward to your help and the help of others on this journey. I really want to get this gem 100% running and beautiful again.
     
    WD5GWY likes this.
  7. KB1SLN

    KB1SLN Ham Member QRZ Page

  8. K9AXN

    K9AXN Ham Member QRZ Page

    Chris,

    I have two pooches Rusty and Fanci. Rusty passed away on Friday and Fanci stopped drinking and eating. Just returned from pet hospital with Fanci. Never knew pooches could have a broken heart when a pal passes just me and my wife. Will be at the console a bit less frequently for a few days but will look at the photos and resume the restore with you.

    Regards Jim
     
  9. KB1SLN

    KB1SLN Ham Member QRZ Page

    100% understand here. I have 3 dogs and sometimes I like them better than my kids. This is just an old radio. Talk soon Jim. Take care
     
  10. WD0GOF

    WD0GOF Ham Member QRZ Page

    P1010018.JPG After seeing the photos, my first question is; How and to what extent did you clean the chassis. Second did the power supply look that way too.
    The buzz when the HV is turned on is most likely the laminations in the core of T301. There are some corrective actions you can perform to quiet the buzz. You can remove the xfmr, remove the clam shell covers and clean inside, varnish under vacuum, etc. If the corrosion is very bad you may have to have it rebuilt. General rule; if it buzzes then it will heat up, if it buzzes it will fail. I would quiet the buzz before going forward.

    My rebuild
    P1010018.JPG
     

Share This Page