Determining if MK 12D has Glideslope Capability

[three-eight-hotel]

Was wondering if anybody knew how I might determine if my MK 12D model has a glideslope receiver built-in? The plane came with CDI without GS indicator, but has another stand-alone NAV w/GS. If I determine my MK 12D has GS capability, I'd like to replace the existing CDI to one with a GS indicator.

 

[dmspilot]

What is your other radio?
I'm guessing if the MK12D had a builtin glideslope then whoever installed it would have already put in a GS indicator and your second nav wouldn't have one.

 

[bradg33]

Check the part number against the install manual, which should list the various versions.

 

[Flybuddy]

Some had a 40 channel internal glideslope receiver and some did not. If you can find the part number just do a google search and you'll probably find it. PN# 03118-0301 does have the internal G/S receiver.

 

[Pat Elliott]

Does it have three antenna connectors on the back of it? or two? Com, Nav, GS-(opt). like a lot of radios from that time, the glide slope receiver was internal to the radio, but the antenna splitter was not.

 

[flyingron]

The service manual says units with glideslopes are distinguished by the third antenna connector (looking from the rear of the pulled out radio, the left most connector is the VOR, there is then either a GS connector or a hole (if no GS), the the edge connector for audio and power, then the COM antenna connector on the right.

The "order" number is right below the serial number on the side of the radio. They all start with 03118 and the last four tell you what it is:

0300 or 0304 are 14V w/o GS
0301 or 0305 are 14V w/ GS
0302 or 0306 are 28V w/o GS
0303 or 0307 are 28V w/GS
(many of them omit the leading zero)

The other clue is that next to the serial number, if it says it weighs 4.1 lbs it has no GS. If it weighs 4.4 lbs, it has GS. The serial number label also lists 14 or 28V. There should also be a cruder 14 or 28V label on the rear of the radio.

Somewhat muddling all this is that the 12D can also channel an external GS receiver, but I suspect if they didn't put in an indicator w/GS, they didn't bother with an external GS.