Transmission1

Hi guys i have a early mk1 cobra 148 gtl-dx that has been epromed but i would like to remove the eprom..radio works fine but i would like it removed..how hard /easy is this ?

thanks.

All depends how good you are with your solder iron,or just cut the wires connected on to the board as close as you can,if you are not to hot with your solder iron.

It can be a bit messy. There's probably tracks cut , and other bits and pieces to do to get it back to the way it was . To be honest I love those kinds of jobs . Stripping them down and spending a few hours rebuilding them . Great fun !

Sammy

cb4ever104 wrote: ↑22 Sep 2018, 15:22 It can be a bit messy. There's probably tracks cut , and other bits and pieces to do to get it back to the way it was . To be honest I love those kinds of jobs . Stripping them down and spending a few hours rebuilding them . Great fun !

Sammy

I'm in agreement with Sammy, there will be much more to it than simply removing the eprom. There most likely be cut tracks so that the MB8719 can be sent different information from the prom to get the extra bands. If it has the UK40 channels it may have a present added to drop the frequency down to end in 1.25 so the coarse shift can be left at top centre.

As the MK1 was harder to add extra bands to than the MK2 (due to the MB8719 PLL) some had the 8719 removed completely and replaced with an MC145106 (the PLL which is found in the MK2) to gain further coverage than the 8719 would permit. As it wasn't a pin for pin replacement the 145106 was added via a veroboard add on. The prom then worked through the newly added PLL.

So, if the PLL has been swapped out and you don't have access to a replacement it wouldn't be worth starting the project.

My advice would be to get it off to Nick (Black Spirit). He's the man for this kind of job.

Thanks guys..i have removed the eprom vero board and all wires from switches ect ect..notice there has been some resistors removed near channel selector also now i have no wires going from channel selector on to the main board..lol i think the resisters thas been reomved are the ones that might be on the piece of vero board..all takes time but i will get there..the radio worked fine before i removed the eprom so just a matter of getting all wires sorted out and some resisters replaced and hopefully it will work again..

listner132 wrote: ↑23 Sep 2018, 17:36 so just a matter of getting all wires sorted out and some resisters replaced and hopefully it will work again..

The good thing is that the 148 GTL-DX is very well documented , so you shouldn't have any issues finding what goes where .

S.