From: "Al Parker" 
Subject: [drakelist] 2-NT changes in mtr ckt?


Hi folks,
    A 2-NT xmtr came home with me from the Benson (NC) 'fest Sun.  It's
the first one I've ever had.  I was told that the meter wasn't working,
and it was obvious that the pwr xfmr had been replaced by 3 separate units
(not too bad looking).  Other than that, it's in reasonable condx, and
does work.  My ser. no. is 212, so it's a very early one, according to
WB4HFN's great resource website which says:
      2-NT s/n 0378 Aug 15, 1968
      2-NT s/n 1640 Mar 27, 1970
      2-NT s/n 1779 Aug 16. 1970
      2-NT s/n 2298 Mar 09, 1972
I think they came out in 1966 originally.
    The skem I have is from the manual found on BAMA, which has a date/sn
code which appears to be 1969, starting with s/n 1001, which agrees with
the above info.
    The meter in my unit is one of those terrible Emico "bang-bang" moving
vane things, I don't know why it didn't work because the coil resistance
is around or < 1 ohm.  I can't get it to deflect even after assuring it's
mechanically OK.  The meter ckt in this early unit is different than what
the skem shows.  This unit puts the meter coil directly in the final
cathode path, thru the common 15 ohm resistor, to ground.
    Anyhow, I've found a "standard type" meter that will fit in, and have
copied the original scale, pasted it to the new meter and installed it,
thinking the ckt was like the schematic, which essentially puts the meter
across the 15 ohm resistor.  I was trying to calibrate it by putting 2.5v
across the 15 ohm res. (which is really 16.6), which would result in 150
ma.
    I guess I will alter the cathode wiring to put the meter across the 15
ohm resistor, but it took me a while to figure out what was really
happening.  Has anyone had an early 2-NT and seen the problem, and do you
have a schematic you could scan for me, just for future reference?
    I hope this info might help somebody along the way.
73,
Al, W8UT
New Bern, NC
BoatAnchors appreciated here
http://www.thecompendium.net/radio/
http://www.hammarlund.info



----------------------------------------------------------------------
Submissions:        drakelist{at}www.zerobeat.net
Subscribe:          majordomo{at}www.zerobeat.net - subscribe drakelist in body
Unsubscribe:        majordomo{at}www.zerobeat.net - unsubscribe drakelist in body
Hopelessly Lost:    majordomo{at}www.zerobeat.net - help in body of message
Brought to you courtesy of TLCHost.net  http://www.tlchost.net/
----------------------------------------------------------------------

---