Had a hard time deciding which section to post this in, hope this is the right one.
Working on an Advent 300 receiver and am having minor issues with the tuner. All aluminum electrolytic caps are new as of yesterday. When aligning the tuner I noticed L501 which is the 2nd coil (out of 2) as well as the second tunable trimmer cap have absolutely no effect. The tuner also has poor sensitivity although does pick up a few stations.
by second tunable trimmer cap I mean the trimmer on the third "final" section of the tuning capacitor.
I am assuming Q501 which is the fet in that section is probably bad. I'm planning on ordering a few replacements as they are available cheap as well as a replacing a few of the ceramic caps in the stage as well.
Sorry for my poor descriptions as i'm not that familiar with tuners, just know the basic alignment procedure and am learning as I go.
I'm using the Schematic from the website below.
http://www.davidreaton.com/PDFs/Advent_300_newer_Tuner_power_supply_schematic.pdf
Any opinions? things I should look for?
Working on an Advent 300 receiver and am having minor issues with the tuner. All aluminum electrolytic caps are new as of yesterday. When aligning the tuner I noticed L501 which is the 2nd coil (out of 2) as well as the second tunable trimmer cap have absolutely no effect. The tuner also has poor sensitivity although does pick up a few stations.
by second tunable trimmer cap I mean the trimmer on the third "final" section of the tuning capacitor.
I am assuming Q501 which is the fet in that section is probably bad. I'm planning on ordering a few replacements as they are available cheap as well as a replacing a few of the ceramic caps in the stage as well.
Sorry for my poor descriptions as i'm not that familiar with tuners, just know the basic alignment procedure and am learning as I go.
I'm using the Schematic from the website below.
http://www.davidreaton.com/PDFs/Advent_300_newer_Tuner_power_supply_schematic.pdf
Any opinions? things I should look for?
got it figured out with the help of an RF engineer at work.
I was looking at the circuit backwords. The coil and trimmer which are linked to the FET on the input are what does not work. The FET is not drawing any current ergo no sensitivity.
MPF280 is impossible to find but it appears J310G is extremely close. If anything it has to be better then nothing atall 😀
I was looking at the circuit backwords. The coil and trimmer which are linked to the FET on the input are what does not work. The FET is not drawing any current ergo no sensitivity.
MPF280 is impossible to find but it appears J310G is extremely close. If anything it has to be better then nothing atall 😀
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