|
Vintage Asylum Classic gear from yesteryear; vintage audio standing the test of time. |
|
|
|
Vintage Asylum Classic gear from yesteryear; vintage audio standing the test of time. |
|
In Reply to: restoring a Pioneer F90, is this component bad? posted by ltman on January 14, 2024 at 14:57:31:
The pictorial in the service manual refers to that as L7, a 100uH choke. However, the schematic denotes L7 as a 2.2uH choke. This part feeds DC tuning voltage to the FM oscillator varactors D1-4, so I'm not sure which value is correct. Mathematically speaking, the XL of a 100uH choke provides greater isolation between the RF at the diodes and the DC tuning voltage. OTOH, it's possible the higher SRF (series resonant frequency) of the smaller value choke is being utilized. A 2.2uH Bourns axial molded choke (part no. 78F2R7K-RC) is specified with a SRF of 95 MHz, which would be about right. In any event, I suspect this isn't the problem. The odd appearance is likely only aging of the varnish used to protect it from humidity and such.
FWIW, I've stopped working on vintage digital tuners due to the large numbers of proprietary ICs and other components that are now unavailable. It's simply not worth the troubleshooting time and effort, so when mine fail, they go in the trash and I buy a replacement. I've discarded a Luxman and a Fisher in just the last few years because of this. The latter was a superb performer with a sound quality that's rare in PLL designs. My current tuner is a Denon TU-660. It needs a new memory capacitor, but otherwise works well. I seldom use FM broadcasts as a source, so I live with this minor inconvenience. My advice in your situation would be to look for a replacement.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Funky Looking Component - Triode_Kingdom 07:09:10 01/15/24 (1)
- RE: Funky Looking Component - ltman 10:24:47 01/15/24 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
