LF Annapolis test, etc.

Frank Gentges gentges@itd.nrl.navy.mil
Sun, 7 Mar 1999 20:55:45 +0000 (GMT)

I thought I had a GR type 1390B noise generator but cannot now find it.  
We need something like this for the test next weekend.  If anyone has 
one to loan let me know.

I have a Krohn-Hite type DCA-50 laboratory power amplifier.  It is rated 
at 50 watts from DC to 500 kHz into a load of 200 to 330 ohms.  It 
derates outside this range.  It features a "pride?", "flock?" of vacuum 
tubes in the output stage.  Where can I place this orphan to get someone 
on the air?

I will bring some antenna bridges to the Thursday meeting and can talk 
about measuring backyard antennas to develop tuning networks.

If anyone wants to build a computer monitored power amplifier take a look at
the Data Acquisition modules at <<http://www.bb-elec.com/shopcatalog.asp>>. 
They have a serial A/D module at
<<http://www.bb-elec.com/product.asp?dept%5Fid=54&sku=232SDA12>> that looks
useful to monitor drain currents, bias voltages, temperatures and control
things like keying etc.  Just build in a 0-5 volt interface with a few
op-amps to supply the standardized input to the A/D from current sensor
resistors, temperature sensors and voltage dividers.  With an old 286 the DOS
based software can log operating parameters so if something goes wrong you
can look at the data leading up to the failure. Just thought someone 
might be interested.

Oh, yes... I need some help with my amateur class at Thomas Jefferson on 
Wednesday afternoons.  Anyone able to help?

Frank K0BRA