>
>One day an "old-timer" touched a small neon? bulb to one balanced line
>output post of my MFJ948 tuner and then touched to the other output post.
>There was a difference in brightness. Is this a useful method to test for
>balance. Is there another test (short of RF ammeters)?
// I use an oscilloscope and HV multiplier to measure the output voltage
on each side of the balanced transmission line. On "Ultimate Transmatch"
type tuners, the imbalance is not small and not moderate.
>My antenna connected was a long-wire
>500' vee sloping from 90' at apex to about 30' at the end of one wire and
>20' for the other wire.. Midway each wire passed over trees which were of
>different heights. What method can one use to bring the antenna and feed
>line into balance--with a standard(?) tuner?
>
1. Remove the variable inductor and one variable capacitor from the
MFJ-948 tuner.
2. Obtain a similar variable inductor and a means of ganging two
inductors. -- Source of cogged belts and pulleys: Small Parts,
Inc.,13980 NW 58 Court, Miami Lakes, FL 33014, telephone [305] 751 0856.
3. Build a balanced L-network tuner on a piece of 3/4" plywood. A
suitable balun is c. 18' of RG-213/u wound on 3" ABS drain pipe. The
ugly balun connects to the input.
4. If you're interested, there's an article on balanced L-networks in
the 2/90 *QST*. This article is also available on my Web site.
cheers
- R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.
end
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