Thread: Pilot U650
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Old 10th Apr 2020, 12:37 pm   #85
David G4EBT
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Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
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Default Re: Pilot U650

Quote:
Originally Posted by Devon60Ben View Post
Thanks very Much David, will study this and refer to your previous posts -
Perhaps in the meantime i should try connecting ipod to my audio preamp then preamp to radio as the power amp?
Yes, if you make up a lead as I shown in the sketch in my earlier post to combine the two stereo channels into mono, then a 0.1uF capacitor to isolate the output of the preamp from the input to the radio's 'Gram socket' that should work fine. To make things a bit clearer, I've redrawn the sketch to show the preamp in circuit. The two resistors and the capacitor can of course be inside the preamp box, so all you'd have is a lead from your phone etc into the preamp, and another lead from the output of the preamp into the gram sockets. On the radios I have, the gram input is two wander sockets, so I just use a short length of twin flex from the preamp output with two wander plugs on the end.

Some may argue that the isolation cap is redundant, but I don't like the idea of connecting an expensive smartphone directly into the gram socket of a valve radio even if - as may be the case - there's an isolation cap in the set.

Hope that helps.
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