Topband: RCS-4 Noise found! by N0AH

[Dinsterdog@aol.com]

no,, not the 80 meter buzz saw-  but rather the noise on my Ameritron RCS-4 I 
asked about earlier- 

Ok, the lowdown is that it turned out to be a AC noise on the line one 
control....

Here is a brief description of how this thing works-

In the antenna 4 postion, no electrical current is sent out to the box and 
the relay's inside the box just direct the RF signal from antenna port 
#4.....right to the control box inside- position 4 is also the default 
position when the unit is off- 

When one selects the third position, a negative DC current travels out on the 
coax from the control box and switches relay 3 up so that the RF signal is 
heard from antenna port #3.

When one selcts antenna port #2, guess what- a positive DC current goes out 
to the relay box and turns up relay 2's arm and you hear the antenna on 
antenna port #2-

So, if we have used no current to get port 4 activated, - DC current for port 
3, and  + DC current for port 2, whats left????  AC!

In the antenna 1 position, on the control box, a AC signal is sent from the 
control box via the coax to the unit outside.  Unlike the other positions, 
the AC is rectified in the outside box!! Where it comes in, the AC signal can 
only go down one traffice lane- to the rectifier cicuit for port #1.......and 
guess what is there- a rectifier circuit that works like a piece of poop- 
somehow, some type of AC signal is getting to the the relay for antenna one's 
position when in fact, it should have been rectified out- 

Thus, this explains why no matter what, any antenna hooked up to position one 
will have the ac noise on it- 

Fixing it on a bench sounds easy but why bother- this is the second RCS-4 
I've tried that has pooped out- I'm getting my money back-  thx to K0RF who 
patiently explained all this to me- 73  Paul  N0AH



--
FAQ on WWW:               http://www.contesting.com/topband.html
Submissions:              topband@contesting.com
Administrative requests:  topband-REQUEST@contesting.com
Problems:                 owner-topband@contesting.com