On 3/4/2015 5:11 AM, Brian Morrison wrote:
On Wed, 04 Mar 2015 05:50:02 -0500
Jerry Stuckle wrote:

On 3/4/2015 2:29 AM, Jeff wrote:

Coax can NEVER be spliced without causing a huge impedance
mismatch at the point of the splice. This is not 60hz or DC. But
any ham with even a minor bit of technical knowledge should
understand this.


We are talking about 200kHz here not 200MHz!! Use could join the
coax with a bit of choc-block at that frequency and not see any
significant performance degradation.

Jeff


It doesn't matter if it's 200kHz. The problem remains.

It depends what you mean by 'problem'.


And yes, there WOULD be s"significant performance degradation" if he
used a bit of choc-block.

That is only true if the discontinuity is a significant fraction of a
wavelength, 200kHz is about a 1.5km wavelength, in coax that would be
about 1km with typical velocity factors. A choc block is about 10mm
long, so it is 1/100,000th of a wavelength. I would not expect any major
problem but it could be used to experiment and cleaned up later if
necessary.


But if you understood ANYTHING about transmission lines, you wouldn't
make such a stupid statement.


Actually it's because Jeff understands about transmission lines that he
makes the statement, it isn't a stupid statement at all in the context
of the OP's question and the technical details of the installation.


I agree with you and with Jeff. At 200kHz, I'm not even sure that the
coax acts as a pure transmission line anyway. I don't remember the lower
cutoff frequency. In any case, that was a good analysis, Brian. Thanks
for that.