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There are PL-259's and PL-259's. Some of the far eastern stuff is "real
crap". If you use geniune Mil-Spec types like real Amphenol's or other
reputable makes you should no problem. I melted the socket on the back of
my FL-2110Z three times before replacing it with a N type connector. Then
no further problems. It seems amps and connectors are no different to
other items we buy. You get what you pay for. Caveat Emptor!
John ZS5JF
----------
> From: Jim Reid <jreid@aloha.net>
> To: amps@contesting.com; henry@qth.net
> Subject: [AMPS] Antenna System Power Ratings Question
To: <amps@contesting.com>
> Date: Tuesday, October 20, 1998 12:12 AM
>
>
> Aloha Big Gun HF amp users,
>
> At what power levels do you have to start worrying about
> antenna system components? All our "stuff": PL259's, N's,
> 9913, LMR-400, typical commercial antennas, switches,
> even the Top Ten devices remote switches, etc. are all
> fine up to and somewhere above the 1500 watt CW,
> RTTY continuous output level. Some antenna tuners
> are rated to 3kW; at least one soon to be for sale,
> the Ameritron ATR-30 will handle a real 3 kW, or
> at least so I am told. I suppose it will have S)239 sockets,
> so maybe they are good to at least that power level.
>
> Any comments on the topic? Up to what powers will
> the usual componentry live, and at what power do you
> have to start upgrading to large hardline, perhaps
> home brew antennas, tuners, etc?
>
> I calculate that at 3 kW, for example, in a 50
> ohm system, with say 2:1 vswr, the RMS voltage
> will be 548 volts; peak voltage, 1.414 times that,
> or at 775 volts, and the RF current will be about
> 11 amps.
>
> Typical good RG8 size coax is rated at 4000 or 5000
> volts breakdown, and yes, as the vswr increases, this
> rating drops, so also the power handling capacity.
>
> In a balance feed/antenna system, using, say 450 ohm
> twin line, and still 2:1 vswr (band edges, say), the voltage
> increases to an RMS of 1640 volts, and peak of 2325 volts,
> and the current, of course drops to about 3.6 amps.
>
> Amidon High Power baluns still use the SO239 socket
> on units rated at 10 kW, I believe.
>
> It would seem the lowest lost system would be the twin line
> feed and balanced tuner, a la, old Johnson AM kW Matchbox.
>
> Just curious,
>
> 73, Jim, KH7M
> On the Garden Island of Kauai
>
>
> --
> FAQ on WWW: http://www.contesting.com/ampfaq.html
> Submissions: amps@contesting.com
> Administrative requests: amps-REQUEST@contesting.com
> Problems: owner-amps@contesting.com
> Search: http://www.contesting.com/km9p/search.htm
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<html><head></head><BODY bgcolor=3D"#FFFFFF"><p><font size=3D2 =
color=3D"#000000" face=3D"Arial">There are PL-259's and PL-259's. =
Some of the far eastern stuff is "real crap". If =
you use geniune Mil-Spec types like real Amphenol's or other reputable =
makes you should no problem. I melted the socket on the back of my =
FL-2110Z three times before replacing it with a N type connector. =
Then no further problems. It seems amps and connectors are =
no different to other items we buy. You get what you pay for. Caveat =
Emptor!<br><br>John	ZS5JF<br><br>----------<br>> From: Jim Reid =
<<font color=3D"#0000FF"><u>jreid@aloha.net</u><font =
color=3D"#000000">><br>> To: <font =
color=3D"#0000FF"><u>amps@contesting.com</u><font color=3D"#000000">; =
<font color=3D"#0000FF"><u>henry@qth.net</u><font =
color=3D"#000000"><br>> Subject: [AMPS] Antenna System Power Ratings =
To: <amps@contesting.com>
Question<br>> Date: Tuesday, October 20, 1998 12:12 AM<br>> =
<br>> <br>> Aloha Big Gun HF amp users,<br>> <br>> At what =
power levels do you have to start worrying about<br>> antenna system =
components? All our "stuff": PL259's, N's,<br>> 9913, =
LMR-400, typical commercial antennas, =
switches,<br>> even the Top Ten devices remote switches, =
etc. are all<br>> fine up to and somewhere above the 1500 =
watt CW,<br>> RTTY continuous output level. Some antenna =
tuners<br>> are rated to 3kW; at least one soon to be for =
sale,<br>> the Ameritron ATR-30 will handle a real 3 kW, =
or<br>> at least so I am told. I suppose it will have =
S)239 sockets,<br>> so maybe they are good to at least that power =
level.<br>> <br>> Any comments on the topic? Up to =
what powers will<br>> the usual componentry live, and at what =
power do you<br>> have to start upgrading to large hardline, =
perhaps<br>> home brew antennas, tuners, =
etc?<br>> <br>> I calculate that at 3 kW, for example, =
in a 50<br>> ohm system, with say 2:1 vswr, the RMS =
voltage<br>> will be 548 volts; peak voltage, 1.414 times =
that,<br>> or at 775 volts, and the RF current will be =
about<br>> 11 amps.<br>> <br>> Typical good RG8 size coax is =
rated at 4000 or 5000<br>> volts breakdown, and yes, as the =
vswr increases, this<br>> rating drops, so also the =
power handling capacity.<br>> <br>> In a balance feed/antenna =
system, using, say 450 ohm<br>> twin line, and still 2:1 =
vswr (band edges, say), the voltage<br>> increases to an RMS of =
1640 volts, and peak of 2325 volts,<br>> and the current, =
of course drops to about 3.6 amps.<br>> <br>> Amidon High =
Power baluns still use the SO239 socket<br>> on units rated at 10 kW, =
I believe.<br>> <br>> It would seem the lowest lost system =
would be the twin line<br>> feed and balanced tuner, a la, =
old Johnson AM kW Matchbox. <br>> <br>> Just =
curious,<br>> <br>> 73, Jim, KH7M<br>> On the =
Garden Island of Kauai<br>> <br>> <br>> --<br>> FAQ on WWW: =
&=
nbsp; <font =
color=3D"#0000FF"><u>http://www.contesting.com/ampfaq.html</u><font =
color=3D"#000000"><br>> Submissions: =
&=
nbsp;<font color=3D"#0000FF"><u>amps@contesting.com</u><font =
color=3D"#000000"><br>> Administrative requests: <font =
color=3D"#0000FF"><u>amps-REQUEST@contesting.com</u><font =
color=3D"#000000"><br>> Problems: =
&=
nbsp; <font =
color=3D"#0000FF"><u>owner-amps@contesting.com</u><font =
color=3D"#000000"><br>> Search: =
&=
nbsp; <font =
color=3D"#0000FF"><u>http://www.contesting.com/km9p/search.htm</u><font =
color=3D"#000000"></p>
</font></font></font></font></font></font></font></font></font></font></f=
ont></font></font></font></font></font></font></body></html>
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FAQ on WWW: http://www.contesting.com/ampfaq.html
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Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
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