| Author |
Message |
    
Steelworker2001
Junior Member
Username: Steelworker2001
Post Number: 40
Registered: 1-2004
| | Posted on Saturday, June 27, 2009 - 2:53 am: | 
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I picked-up another older Grant XL Philly model. Keyed it up in the mobile and the locals went crazy - said it sounded awesome. Incredible audio was the report.
HOWEVER ---
Transmitted on sideband and locals said it sounded terrible!. Garbled.
I pulled the covers and discovered that Q-24 is missing.
Question: I know that it is AMC, but what exactly is Q-24 (part?) and where can I get a replacement?
Thanks in advance for the help.
Steelworker
Ken
CEF-809
----
Cobra 148 GTL (1992), Grant XL (Philly), Washington 858, Texas Star DX500
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Steelworker2001
Junior Member
Username: Steelworker2001
Post Number: 41
Registered: 1-2004
| | Posted on Sunday, June 28, 2009 - 1:05 am: |
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Did a little more digging and discovered that the part is identified as:
C458
C
7F 4
I assume that "C" stands for capacitor?? I don't know what it is but I'll keep looking!
Ken
Ken
CEF-809
----
Cobra 148 GTL (1992), Grant XL (Philly), Washington 858, Texas Star DX500
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Steelworker2001
Junior Member
Username: Steelworker2001
Post Number: 42
Registered: 1-2004
| | Posted on Sunday, June 28, 2009 - 1:40 am: |
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Got it......I think.
2SC945
NTE85 / Silicon NPN Transistor
$1.25 at Mouser Electronics
Ken
CEF-809
----
Cobra 148 GTL (1992), Grant XL (Philly), Washington 858, Texas Star DX500
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 4592
Registered: 7-2004
| | Posted on Sunday, June 28, 2009 - 8:41 am: |
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q24 is the AMC for SSB, controls modulation, or in essence SSB power peaks. yes it is a 2sc945 transistor. removing it totally & keeping the audio sounding good CAN be done if care is taken with power mic/gain and mic gain controls. best bet is to reinstall then cut the trace from the center leg of that transistor & bridge it with a 1.5k resistor. while you're in there, if they weren't already changed, change the 10k resistors at r124, r126 & r131 to 4.7k. unless already removed, lift r131 & put a switch on it. you may need to put ferrite beads on switch leads. |
Steelworker2001
Junior Member
Username: Steelworker2001
Post Number: 43
Registered: 1-2004
| | Posted on Sunday, June 28, 2009 - 12:22 pm: |
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Thanks Pat!
Ken
CEF-809
----
Cobra 148 GTL (1992), Grant XL (Philly), Washington 858, Texas Star DX500
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