Re: [Moon-net] Protecting preamp when running 1.5 kw WSJT?
- 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.
--- 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@..., firstname.lastname@example.org
> Date: Friday, July 31, 2009, 1:26 AM
> Hi Bill,
> when you consider the CZX-3500 have a look at the tohtsu
> homepage first:
> 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:
> I think you can't get a better one and the price is really
> 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
> > 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
> > Thanks for info and 73, Bill NZ5N
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