[TowerTalk] 6 pack, int relay's

Jim Thomson Jim.thom at telus.net
Fri Jan 1 05:06:18 PST 2010

:::: My guess? The six pack is notorious for intermittent relay contacts.
I had several of them for years and I was always needing to yank the 
feedlines around on them till the rcvr would come back to life or the sudden 
high swr would go back to normal.

For a while I found that raising the voltage to 15volts or so would make it 
behave better, but ultimately we just learned to notice when it was 
happening, go to where the boxes were, and smack them around a little :-)

Seriously though, unless you really need them, like for two operating 
positions, I would try to use an old fashioned coax switch instead. This is 
just my personal experience, but we found a lot of others who went thru 
this. This was 5 years ago, but maybe they made them better now?


##  I own  six pack  SN  001 !     It has never been used outdoors. 
Originally,  it had only 6 x relays,, then I added the other 6
later on.  I only used the left bank.    I can see that the interlocking
 arrangement  between  left and right banks of relay's  could easily
 be  a problem. 

In any of these box's, u have 2 x choices,  let moisture seep out the 
bottom.. or seal em up super tight... and use a resistor inside to
apply heat  24/7.    I also pack em  with silica gel, [desiccant] , but
only if they are sealed shut. 

Mine has gold contacts.. so one would think this would eliminate
potential problems.   On a similar note... I have had nothing but
problems with all my F-12  relay box's [ 80 and 40m]

They use  P+B  / deltrol  DPST  30 A contacts.  My 'fix'  for em
was to silver plate em with.. 'cool amp'   http://www.cool-amp.com/ 
all contacts.  Then use  'conducto lube'   [same co]  on em.
Conducto lube is just silver powder suspended in grease......and made
for sliding contacts.  You end up with zero ohms every time. 

On some of this stuff... I get  really fed up... and use vac relays. 

I designed a 1 in 9 out remote switch box for a buddy.. which used
surplus  277 vac rated  DPDT   mech relays  [12 vdc]  zero problems in several yrs of use.
It has 10-12 kw stuffed through it all the time.   If I can dig up the url of the surplus place
I will post it here, they have hundreds of em left.   All 'wiring'  done with wide flat cu strap.
7-16 dins used every where.   Those cheap relays run  superb... and no heat, silica gel, or
silver plating used....yet. 

In any event, I'd use  high swr protection as well.  Mine [a] opens up the key line,
and also [b] applies neg Vdc  to the xcvr's alc buss.... and [c] activates the xcvr's inhibit
lead.    I use the array solution's  latest wattmeter.. with a twist.    I run TWO display unit's
in parallel on each coupler.... so I can monitor things in two places.   That also allows u to
use two sets  of alarms... like above, for more than one way of shutting down the amp + xcvr
Both display units  read identical, unplug one of em.. the remaining one still reads the same. 

Later.... Jim   VE7RF

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