Topband: line for beverages

[RA6LBS]

Hi All,


HL> The 450 ohm ladder line that everyone buys is actually by my measurements
HL> 374 ohm.  W8JI measured 377 ohm. We joked about it being the impedance of
HL> free space, 377 ohms.  But it will work in a bi-directional Beverage
HL> application with no real receiving differences on 160.

another very good solution is to use military type telephone twisted
line which is very strong (it has some steel as well as copper stranded
wires), holds for decades (it has UV protected coat) and its impedance
is about 145 ohm. Works fine here and no difference at all with the
classic open wire line.

Some photos:

matching unit:
http://www.ra6lbs.ru/4271.jpg

switching of the direction is done by injecting 12V into the coax line


and the reflection transformer:
http://www.ra6lbs.ru/4248.jpg




-- 
Andrei,
RA6LBS                          mailto:ra6lbs at volgodonsk.ru

                                ICQ 342547543
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