[BC] Maintanence Log

[donroden at hiwaay.net]

Here I go chasing another bunny down the hole......

ex-930khz tower ( ahem.... *assuming* it was a 1/4 wave when built )

then it would possibly be 250 feet tall.

Currently on 1240khz and the previous ( deceased ) engineer matched it with a
C/L/C pi-network.

This antenna has been operating fine for over twenty years.

A kilowatt SX-1A won't null on the Phase Null position ... .40 is as  
low as it will null.  Seems strange, because I've seen SX-1As null at  
40 through 60 ohms.

Lots of fold-back or pdm kill  under modulation peaks.

A dummy load at the ATU will Phase Null to ZERO, and SX1 will modulate fine.

A OIB-3 shows 52+10 indicated when I took power down to under 50 watts  
just to keep the SX-1 making a solid carrier with no modulation.

All three C/L/C components are fixed with no markings.

I can faintly see a .002 on one of two stacked output caps to  
ground.... maybe the second cap is also a .002 ( ?? )

At 1KW no modulation, the antenna current meter ( WOW they actually have one )
reads around 1.5amps which equates to 440R.

The OIB-3 never found a good null for either R or j on the antenna feed.
but there was  a broad semi-null around 450R.

I'm thinking the taller tower might be +200j but I couldn't find it.
Maybe interference from the 950 a mile away. ( maybe not ).

I've always trusted the OIB-3, and will test it tomorrow .... never seen it
do like this afternoon.

Don R