I'm working on a 10-153 Zenith and after a total recap and resistor check out, the radio started doing something strange. When I tune in a good radio station, the radio play great but if I remove the antenna from the radio it starts motor boating. With the radio antenna
hooked up and I tune off frequency, the radio starts motor boating. If I change bands it starts motor boating.
I cleaned all of the contacts on the band switch and also found out the band switch will not move to band C.
I looked at the band switch and there is a stop on the switch on the shaft by the bearings.This looks like a factory band switch. Any ideas.
Bob.

Robert, is it posible someone took the switch apart at some time and did not orient it correctly when replacing it? The switch obviously was meant to go into all band positions. PL

:I'm working on a 10-153 Zenith and after a total recap and resistor check out, the radio started doing something strange. When I tune in a good radio station, the radio play great but if I remove the antenna from the radio it starts motor boating. With the radio antenna
:hooked up and I tune off frequency, the radio starts motor boating. If I change bands it starts motor boating.
:I cleaned all of the contacts on the band switch and also found out the band switch will not move to band C.
:I looked at the band switch and there is a stop on the switch on the shaft by the bearings.This looks like a factory band switch. Any ideas.
:Bob.
:

:I'm working on a 10-153 Zenith and after a total recap and resistor check out, the radio started doing something strange. When I tune in a good radio station, the radio play great but if I remove the antenna from the radio it starts motor boating. With the radio antenna
:hooked up and I tune off frequency, the radio starts motor boating. If I change bands it starts motor boating.
:I cleaned all of the contacts on the band switch and also found out the band switch will not move to band C.
:I looked at the band switch and there is a stop on the switch on the shaft by the bearings.This looks like a factory band switch. Any ideas.
:Bob.
:
Hi Robert,
Someone was on the forum with a similar problem recently. Motorboating is usually caused by oscillaiton in the IF section. You may want to check the wiring after the recap in the IF and RF sections.
About the band switch. I have seen two band radios of this vintage. The police moved to different frequencies in the late 1930's making the police band useless. Zenith eventually dropped the band from new radios.

Best Regards,

Bill

The thread on motorboating is "Zenith 5R216 troubles." I think Edd got the guy straitend out.

Best Regards,

Bill

:I'm working on a 10-153 Zenith and after a total recap and resistor check out, the radio started doing something strange. When I tune in a good radio station, the radio play great but if I remove the antenna from the radio it starts motor boating. With the radio antenna
:hooked up and I tune off frequency, the radio starts motor boating. If I change bands it starts motor boating.
:I cleaned all of the contacts on the band switch and also found out the band switch will not move to band C.
:I looked at the band switch and there is a stop on the switch on the shaft by the bearings.This looks like a factory band switch. Any ideas.
:Bob. http://www.renovatedradios.com/article%20pages/sparton_1068.html Hi Bob, I ran across this article and it made me wonder if this could be why your band switch was disabled. Paul
: