[TowerTalk] Ameritron RCS-4 and noise?

[Roger (K8RI)]

Jon Casamajor wrote:
> I have used the Ameritron RCS-4 to switch antennas on my tower for probably
> 19-20 years with zero issues. I recently re-worked my single tower stack and
> while we were doing that, replaced the RCS-4 switch components.  My stack is
> on QRZ so I won’t describe it here. In the past few days I have a S9+60dB
> noise level on 40m that is pretty much constant. The noise on my SteppIR,
> 20m tune, starts off about the same but settles down to maybe S2 or less,
> about what I would expect for conditions.
>   

Is that the RCS4 with a control cable or the one that gets its signal 
from the coax? I have two RCS-8s that are direct controlled (IE separate 
wires) and I have added jumpers to short out all connectors but the 
active one. I did rebuild one, but that was replace all the coax 
connectors. They were in really bad shape. The threads of the PL-259s 
were just about bonded to the connectors which pretty much destroyed the 
RCS8 connectors when I removed the PL259s. Even if they look pretty, if 
the threads are ruined they aren't much good for reuse.

I now put a thin coating of silicone on them, the mating threads, and 
use flooded heat shrink tubing over the whole works. I make sure not to 
get any of the silicone on the coax jacket as I want the flooded heat 
shrink bonded to it.
> My 2 el 40m Yagi loads up fine and plays with a 1.1:1 SWR at the low end
> which is where it is tuned. I am suspicious that I have a problem with the
> relay box at the top of the tower that is causing the extreme noise. (makes
> 40m completely useless) I’ve swapped out shack consoles for the RCS-4 with a
> spare. If I leave it on the 40m position for an hour or so, it will
> eventually blow the 1A fuse in the console with the +60dB noise level.
>   
Sounds like a relay is not closing which would cause excessive current. 
If your's is the direct wired unit, check each lead for current. If one 
relay isn't closing it will show a higher current. Often the relays have 
to be adjusted when first installed.

Good Luck,

Roger (K8RI)
> I feed the tower with a buried ½” hard line to the tower and low loss LMR400
> up to the switch. I also have VHF and UHF Yagi’s on the stack that are fed
> with separate hard lines and nothing has changed with those feeds.
>
> If anyone has any ideas I would sure appreciate the input.  I am suspicious
> that the relay may be hanging up and putting the AC switching voltage back
> onto the feed line somehow.
>
>  I’ve had Pacific Gas and Electric, our power provider, out here and he took
> a “picture” of the noise and agreed it was horrible. They are still looking
> for problems and have found a very noisy pole maybe a mile away. They have
> been great with their response and support in looking for the problem. I’m
> out of ideas! :-(
>
>  
>
> Regards,
>
> Jon-K6EL
>
> k6el at comcast.net
>
>  
>
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