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Re: [Moon-net] Protecting preamp when running 1.5 kw WSJT?

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  • Bill Dzurilla
    Thanks, Rainer, and thanks to others who responded privately. I had noticed that the CZX-3500 is rated at 1 kw PEP at 150 mhz on the Tohtsu page but at 2 kw by
    Message 1 of 1 , Jul 31, 2009
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      Thanks, Rainer, and thanks to others who responded privately.

      I had noticed that the CZX-3500 is rated at 1 kw PEP at 150 mhz on the Tohtsu page but at 2 kw by Henry Radio and RF Parts. I was inclined to accept the manufacturer's own rating, but 3 people have told me that they have been using the CZX-3500 for years with no problems with 1.5 kw. I have also heard good reports about the CX-600NL.

      Thanks for the tip on the Relcomm relays. That is a really good price, although again the rating is 1 kw. Also, these are 24v relays, and my sequencer supplies 13.8v.

      At this point, I'm still not sure what I'll do. It looks as though 2 relays, a weatherproof enclosure, and a second coax line are needed at minimum.

      73, Bill

      --- On Fri, 7/31/09, Rainer <df6na@...> wrote:

      > From: Rainer <df6na@...>
      > Subject: Re: [Moon-net] Protecting preamp when running 1.5 kw WSJT?
      > To: "Bill Dzurilla" <billdz.geo@...>
      > Cc: moon-net@..., wsjtgroup@yahoogroups.com
      > Date: Friday, July 31, 2009, 1:26 AM
      > Hi Bill,
      >
      > when you consider the CZX-3500 have a look at the tohtsu
      > homepage first:
      > http://www.tohtsu.com/shouhin.holder/CZX-3500.html
      >
      > There are still some companies rating that relay for 6GHz
      > and with double the power
      > (and even more) than Tohtsu themself.
      >
      > If you really want a good relay have a look here:
      > http://cgi.ebay.com/NEW-NEW-Relcom-1000-Watt-RF-RELAY-DC-2-GHz-NEW-NEW_W0QQitemZ300328484077QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45ecf8fced&_trksid=p3286.m20.l1116
      >
      > I think you can't get a better one and the price is really
      > good.
      >
      > 73, Rainer
      >
      >
      >
      > Bill Dzurilla schrieb:
      > > Could someone give me ideas on how to protect a
      > mast-mounted preamp when transmitting a full 1.5 kw in WSJT
      > modes?
      > >
      > > I had first hoped that the SSB MHP-145 would be a good
      > solution, but its 1.5 kw rating is only for CW/SSB.  It
      > only can handle 750w in continuous carrier modes.
      > >
      > > I have also looked at Al's set-up at wa4ewv.net and
      > other similar 2 relay, 2 coax systems.  It seems that
      > the Tohtsu CX-800N and CZX-3500 are popular choices. 
      > But these are rated at 1,000 watts and I'm concerned if they
      > can handle 1.5 kw.  Some have told me that it's not an
      > issue due to line losses that reduce power at the antenna to
      > near 1,000 w, even if there is 1.5 kw coming out of the
      > antenna.  But I only have a short coax run and should
      > be able to deliver well more than 1,000 w to the antenna
      > with my Lunar Link amp.
      > >
      > > If you have any ideas for relays or diagrams of a
      > complete system, please let me know.  My transceiver is
      > an IC-7000 and it is not easily modified for a receive-only
      > antenna jack, which some folks have done with other, larger
      > transceivers.
      > >
      > > Thanks for info and 73, Bill NZ5N
      > >
      > >       
      > > _______________________________________________
      > > Moon-Net posting and subscription instructions are at
      > http://www.nlsa.com/nets/moon-net-help.html
      > >
      > >   
      >
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