[BULK] - Re: [TowerTalk] ARR Preamp Failures

[W0UN -- John Brosnahan]

Well, Jim--I don't really think you have ANY room to be pissed off.
The data sheet for the ARR auto-switched preamps says THREE TIMES
that the auto-switching is rated to 25 watts.  Did you actually read
the data sheet?   It is only ONE PAGE long.

I would have to say that Jay has done a COMMENDABLE job by
repairing your unit repeatedly while you run it way over SPEC.

--John  W0UN

 From the ARR data sheet   http://www.advancedreceiver.com/page7.html

Features:

• Low noise figure
• Automatically switches off during transmit
• 25 watt through power capability
• No transceiver modification necessary
• High immunity to overload
• Completely shielded
• Small size
• Rugged low profile custom enclosure
      (and)
The rf relays used in the preamplifier will handle up to 25 watts of rf power.
      (and)
Connected in this manner, the preamplifier need only handle the transceiver 
power (25 watts or less).



At 12:38 AM 10/5/2004, you wrote:
>On Mon, 4 Oct 2004 09:16:26 -0700, Steve Katz wrote:
>
> > But I sure wouldn't rely on an RF-activated T-R
> >switching scheme, at any power level.  Use "hard keying," with sequencing to
> >be sure the preamp is bypassed before the exciter can generate any power.
> >ARR used to sell a 4-port (or maybe more than 4?) sequencer as an
> >accessory...maybe they still do.  Ask Jay!  -WB2WIK/6
>
>Thanks, Steve.
>
>If that is true (and I don't doubt you), why would ARR not say that on 
>their data sheet
>and/or instruction sheet (and why would they include a sensing circuit in 
>the amp that
>doesn't work?)? I'm a believer in "if it isn't on the data sheet, it 
>doesn't count" and "if
>it's listed as a feature in the sales lit, it damn well ought to work, 
>real good."
>
>Who is Jay and how do I reach him?  Does he work for ARR?  I've written to 
>ARR
>three times and included the letter with the preamp when I returned it for 
>service and
>the ONLY response I've gotten from them was a cryptic note on the last repair
>invoice (no charge) telling me that 10 mW was the max input level spec. Why
>wouldn't they tell me not to use auto sensing?  Why would they include an 
>auto
>sensing circuit if it doesn't work reliably (i.e., resulsts in destructive 
>failures)?
>
>The bottom line is that I'm pissed off by this mentality of "you ought to 
>know that our
>stuff doesn't work the way it's advertised."  I'm an EE and systems 
>designer, and I try
>to make a habit of reading the doc that mfrs provide. If I don't, shame on 
>me. If they
>don't provide it, shame on them. This preamp was sitting in my shack when 
>it failed
>four times. I would be ten thousand dollars more pissed off if it had been 
>on a tower.
>
>Jim Brown K9YC
>
>
>
>_______________________________________________
>
>See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless 
>Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with 
>any questions and ask for Sherman, W2FLA.
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk at contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk