Syntech I VCO Mod/Adjustment??

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kb0nly
Posts: 20
Joined: Mon Jun 04, 2007 3:16 am
Location: Tyler, MN

Syntech I VCO Mod/Adjustment??

Post by kb0nly » Mon Dec 01, 2008 2:39 am

I have a Syntech I 70-530 that was programmed:

442.000 RX
447.000 TX

We just changed it to:

449.850 RX
444.850 TX

Display shows 95 after powering up, that was expected, VCO unlock.

According to the service manual i should adjust L702 while monitoring the test point T701 and set it for 5.5v. Can't do it, its at 6.89v and that's where it stays, i moved that slug from top to bottom three times in a small increments and watching the meter while moving it up and down, voltage doesn't change.

What do i need to do to get the VCO to lock???
"Bite My Shiny Metal Ass!"

Andy Brinkley
Posts: 68
Joined: Tue Jun 03, 2003 8:23 pm
Location: North Carolina

Re: Syntech I VCO Mod/Adjustment??

Post by Andy Brinkley » Mon Dec 01, 2008 8:18 pm

Scott -

Sounds like it was reprogrammed with a wrong header code.

Did you read the memory module and edit the data or try to create a codeplug from scratch?
Andy

--------------------------------------------------------------
NC Certified Firefighter III / EMT-A
FCC Licensed Technician / Amateur Call NC4AB
http://www.brinkleyelectronics.com

User avatar
kb0nly
Posts: 20
Joined: Mon Jun 04, 2007 3:16 am
Location: Tyler, MN

Re: Syntech I VCO Mod/Adjustment??

Post by kb0nly » Mon Dec 01, 2008 8:37 pm

I figured out the problem, the 2716a editor that i got off the MidlandLMR yahoo group was only intended for VHF radios. Too bad the guy didn't make one for UHF also.

Anyway, problem solved. Used the 70-1000C software to fix it. I pulled the memory module and desoldered the Eprom, read it, modified the file in the 70-1000C software, saved the file, loaded the file with my eprom burner, erased the eprom with uv, burned, and dropped into the radio. All is well.

Glad i don't have to do that very often!

Thanks for checking in.
"Bite My Shiny Metal Ass!"

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