Thomas,
Here's one for ya. The last RCA (16T2) table model I did, had a SOLID copper wire wrapped around the frame (rectangle) of the rear panel, then stranded from a tie point to the chassis for SW band. It worked,
but not as good as a long wire. This 67V1 has a #22 STRANDED wire across the lower back, one side and the front (3 ft horizontal U shape), then up about 2 ft to the radio chassis. I'm thinking a larger solid wire to a tie point near the chassis then stranded into the set for better SW operation. I'll be replacing it anyway, but will this method yield any noticable improvement over the original?

marv

Marv, my thinking is that stranded wire is best for applications that must physically flex. Otherwise, even for SW, I wouldn't expect a difference between solid and solid conductors.

:Thomas,
:Here's one for ya. The last RCA (16T2) table model I did, had a SOLID copper wire wrapped around the frame (rectangle) of the rear panel, then stranded from a tie point to the chassis for SW band. It worked,
:but not as good as a long wire. This 67V1 has a #22 STRANDED wire across the lower back, one side and the front (3 ft horizontal U shape), then up about 2 ft to the radio chassis. I'm thinking a larger solid wire to a tie point near the chassis then stranded into the set for better SW operation. I'll be replacing it anyway, but will this method yield any noticable improvement over the original?
:
:marv

According to what I've learned on here, stranded allows for better conduction, since high frequency alternating currents tend to run on the skin of the wire. More skin makes for better conduction.

Thomas

Of course I've also learned that shorts between the strands will cause small rf "coils." This is why Litz wire has each strand insulated. A clear example I accidently made for myself was my FM radio, and certainly with the high frequencies of FM, extra loops will make a dramatic difference. Well, for this radio I purchased a tuning condenser from England because I couldn't find a local 50 or less pF. The particular unit is unique because it's mounted on slate. Each end of the condenser is mounted to slate, and the center of the two units has spring contacts which contact the shaft. Well, since the rotor isn't connected to a unified frame, it instead has these extra loops to conduct through. The spring contacts and the end pieces actually become part of the induction circuit. Shorting them all together actually changes stations (and stabilizes things). Not sure which way is better, but Mr. Litz evidently found that insulating the individual strands was better so that small resonant circuits would not be created within the larger circuit. Certainly you want each strand of wire in your antenna to respond to the exact same frequencies for an efficient antenna. With some of them shorted, they won't respond to the same frequencies as the otheres with the same capacitance.

Thomas

Thomas,
Since it's a horizontal "U" shape, would a similar vertical "U" shape work better? Like down from the radio, across the front, then back up the other side, and open-ended.

marv

:Of course I've also learned that shorts between the strands will cause small rf "coils." This is why Litz wire has each strand insulated. A clear example I accidently made for myself was my FM radio, and certainly with the high frequencies of FM, extra loops will make a dramatic difference. Well, for this radio I purchased a tuning condenser from England because I couldn't find a local 50 or less pF. The particular unit is unique because it's mounted on slate. Each end of the condenser is mounted to slate, and the center of the two units has spring contacts which contact the shaft. Well, since the rotor isn't connected to a unified frame, it instead has these extra loops to conduct through. The spring contacts and the end pieces actually become part of the induction circuit. Shorting them all together actually changes stations (and stabilizes things). Not sure which way is better, but Mr. Litz evidently found that insulating the individual strands was better so that small resonant circuits would not be created within the larger circuit. Certainly you want each strand of wire in your antenna to respond to the exact same frequencies for an efficient antenna. With some of them shorted, they won't respond to the same frequencies as the otheres with the same capacitance.
:
:Thomas

Not sure. Give it a whirl. If this piece of wire is actually a coil, like any other loop antenna, then it may work better on a vertical plane. If it's an open ended wire, folding it back on itself in any plane is detrimental to the signal. The short wave loop (one turn of wire) in my V170 (similar to the 16T2) was laid in a vertical plane when the chassis was inside of the phonograph consol. I assume that the 16T2 has the short wave loop in this same plane. The loop in my set was a solid piece of copper wire, around 25 gauge, maybe 24. Experiment and see what happens.

Thomas

Thomas,
The 16T2 made a complete loop around the rear panel.
This 67V1 has 3/4 turn loop, doubling back across the front and up to the chassis, creating a horizontal "U" shape. I gather from some of your postings of the past, that this arrangement of parallel conductors in the same horizontal plane will cancel signal energy, whereas a similar vertical arrangement will not cancel the signal energy. Am I correct?

marv

:Not sure. Give it a whirl. If this piece of wire is actually a coil, like any other loop antenna, then it may work better on a vertical plane. If it's an open ended wire, folding it back on itself in any plane is detrimental to the signal. The short wave loop (one turn of wire) in my V170 (similar to the 16T2) was laid in a vertical plane when the chassis was inside of the phonograph consol. I assume that the 16T2 has the short wave loop in this same plane. The loop in my set was a solid piece of copper wire, around 25 gauge, maybe 24. Experiment and see what happens.
:
:Thomas

Folding over in any case causes cancelling of the signal, whether it be on a horizontal plane or a vertical plane. However, this only holds true with open ended wires. Coils, like a loop antenna, or any other coil, have wires that fold back on eachother over and over again. If this U shaped wire is an actual coil, with both ends connected to a tank circuit in the radio, then it's supposed to go around in a circle, or semi-circle, depending on what kind of impedance you need.

Thomas