[Amps] Amplifier for 630 meter band

[Jim Thomson]

Date: Sat, 11 Nov 2017 05:43:56 -0700
From: Richard Solomon <dickw1ksz at gmail.com>
To: Amplifiers <amps at contesting.com>
Subject: Re: [Amps] Amplifier for 630 meter band

<Probably the wrong place to ask, but,
<what are folks using for Antenna's on
<630 Meters ?

<73, Dick, W1KSZ

##  My guess would be the tallest wire vert, or tower u could erect, like a 
100 ft tall cage wire between 2 trees, with Top loading provided by the catenary
line on one or both sides, then a huge base loaded coil. 

##  back in 1974, I worked a brief stint with fed govt MOT at a marine station, which
was all on CW, and  500 khz and below, like down to 420 khz.   During our summer time, we could
hear marine traffic from  zl  + vk land the odd night.   As is, it baffles me how folks from 
Zl + VK can hear NA stations on 160m, during the winter months here in NA.   Trying to hear
VK + ZL on 160m, during my summer months is a dogs breakfast, noise packed, static crash
filled mess.   

##  137 khz, gimme a break, now its gone too far.  As far as using audio gear,  dont confuse
freq response with bandwidth,  2 different things.  Freq response could be quoted as 20 hz to
20 khz, but the BW of the same audio amp could easily be 3 hz to 200 khz. 

##  I worked out some typ  PI and PI-L values for typ and  various plate load Zs.   On paper,
a  PI  or PI-L  for  630M band,  472-479 khz is not an issue,  but requires a lot of padding
of both the tune and load cap.  The main tank coil can be made with smaller gauge wire, due to skin effect,
but more coil is required...... like almost quadruple that of a 160M amp.     Still it would be a fun project
for a GG triode amp.   I would design it and  build it just as a challenge,  but no practical use on my city lot.
A 50 ohm dummy load would be the only load it would ever see.      Bird at one time made a 500 khz to 2.2
mhz elements for its 43 and other line sections.   They might work  ok at 472 khz.   Or just measure the V
across the 50 ohm load... good enough. 

later... Jim   VE7RF