Superstar 360 FM question

Ron Fouler · Post by **Ron Fouler** » Tuesday 1st Aug 2006, 10:50

Those that have one of these will know they're based on the Mk1 Cobra 148 GTL-DX, and also they have BLOODY AWFUL FM deviation! And that brings me cunningly to my problem; how do I change the bloody awful FM transmit audio? I've already put an Astatic "Teardrop" on it, and even with the tone as high as it'll go it's not THAT great.
Also, how do I find the roger beep circuit, cos I wanna reconnect it. Anyone got a schematic for one of these?
Thanks in advance.

zodiac · Post by **zodiac** » Tuesday 1st Aug 2006, 11:39

Ron,
The Superstar you have is it the MK1 or the MK2, the reason i ask is that both of them are the same as the MK1 and MK2 Cobra 148GTL DX but the MK1 sounds as you said on FM if you turn the deviation VR up too far, it makes them sound like a Cybernet Multimode 2 for the same reason overdeviation. The MK2 sounds much better on FM you can turn the deviation up on them without any problems as long as you don't go too high.
As for the schematic, there will be one available very soon on a CD for both the MK1 and 2 that's being re-drawn at the moment with loads of extra information on it to make it easier to follow for people like me. I can't wait to get my hands on one when it's finished, I've seen part of it and it's nothing like you've ever seen before plus it's being done in England so there won't be a problem with the postage.
Dave.

zodiac · Post by **zodiac** » Tuesday 1st Aug 2006, 12:08

Ron,
Forgot to mention, the beep transistor on the MK2 is TR33, not sure if it's the same for the MK1 but you can check it out to see if it's got one of the pins lifted as that will stop it working. You'll find it at the front right hand side about 1/2 inch in and 1 inches from the front edge on the MK1, the MK2 it's 1/2 inch in and 1/4 inch from the front.
Dave.

Ron Fouler · Post by **Ron Fouler** » Tuesday 1st Aug 2006, 22:15

Cheers, Zody. I'm assured this is the Mk1 based one (it has the Mk1 chip near the channel switch). I'll have a gander for the beep

Which VR is for the FM dev, do you know?

zodiac · Post by **zodiac** » Wednesday 2nd Aug 2006, 0:07

Ron,
It's VR5 on the MK2 and I'm sure it's the same on the MK1. You'll find it to the right of the 8719 PLL. There are two of them you want the first one , don't touch the other VR7 it's the carrier balance for SSB.
Dave.

Ron Fouler · Post by **Ron Fouler** » Wednesday 2nd Aug 2006, 1:51

Cheers, zody.

zodiac · Post by **zodiac** » Saturday 5th Aug 2006, 13:22

Ron,
It's VR3 on the MK1, and VR5 on the MK2. I just had a look on the open channel site in the UK.
Dave.

Ron Fouler · Post by **Ron Fouler** » Saturday 5th Aug 2006, 21:09

thanks, mate