On Sat Jul 20 22:15:21 EDT 2019, paul swed wrote:
Chris
Looked at the photos and believe you do not need a down converter. The one
pix has a filter in it. dcf21r57. Its a murrata GPS bandpass filter 1575
MHz.
So that indicates its looking for a antenna. See what voltage is on the
antenna jack.
Chris,
I'll post photos of my Trak 8810 if it will help with your restoration.
Yes, it contains a Magnivox MX 4200 OEM GPS receiver with serial
interface and 1PPS via SMA connector.
I fired up the 8810 for the first time since maybe the late 1990's and
after about 20 minutes it's tracking 6
Chris
Looked at the photos and believe you do not need a down converter. The one
pix has a filter in it. dcf21r57. Its a murrata GPS bandpass filter 1575
MHz.
So that indicates its looking for a antenna. See what voltage is on the
antenna jack.
On Sat, Jul 20, 2019 at 9:58 PM paul swed wrote:
>
Chris
What Bob was mentioning is true of the older units circa 1990s. I have
homebrewed down converters for two older units. Essentially everything gets
multiplexed onto the one jack so you can't really tell by looking if it
needs a downconverter or just an antenna. A bit of a hint. If there is
Hi
It’s a pretty good guess that a device from that era ran a “downconverter” head
end.
They had a full RF front end out at the antenna and fed some sort of IF
frequency
back to the unit. Various outfits had approaches to how to do it. The net
result is that
the head end is pretty specific to
Hi,
Bought one of the above gps clocks at a radio rally last
Sunday. Looked ok on the outside, but severe corrosion
from a leaked backup battery inside. Cleaned all that up,
replaced some caps and a few other parts on the psu board
and now at least partially working. All the menus seem to
work,
