[TowerTalk] RCS-4 and noise

[Jon Casamajor]

Hi Roger,

Thanks for your thoughts. Yes, the RCS-4 is the model that puts an AC
voltage on the coaxial cable and does not use another control line.

The relay box that I'm suspecting trouble with is a new one that worked fine
for several months since my tower re-build in late July, 2008. The original
unit that I had up there for a long time was Ameritron built and of course
the current one is MFJ built.  It has been suggested by another member that
I may want to re-solder the relays on the board as he found some cold solder
joints on his.  I will crank the tower down and have a look at that issue
after I exhaust some other suggestions today.

Thanks again for your inputs and HNY!

 

Regards,

Jon-K6EL

k6el at comcast.net

------------------------------

 

Message: 6

Date: Wed, 31 Dec 2008 17:42:58 -0500

From: "Roger (K8RI)" <K8RI-on-TowerTalk at tm.net>

Subject: Re: [TowerTalk] Ameritron RCS-4 and noise?

Cc: towertalk at contesting.com

Message-ID: <495BF572.8020407 at tm.net>

Content-Type: text/plain; charset=windows-1252; format=flowed

 

 

 

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 ?? 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

> 

>  

> 

> _______________________________________________

> 

> 

> 

> _______________________________________________