Mac 1700 Indicator Quandry

[Gomer Pound]

I have a Mac 1700 (serial number one!) with what I believe is a King KI 214 indicator. The 214 has a built in glide slope receiver. Either the GS receiver in the KI 214 is off, or the 214 indicator is off (sticking.) I have read the KI 214's are no longer repairable, plus need GS frequency adjustments to each channel. I can buy a replacement KI209 which does not have a GS receiver, which means I would need an external GS receiver. I can buy a used KN75 digital GS receiver for around $400 with an 8130. I believe the Mac 1700 is still a good radio, but I don't know if it's worth the installation costs to add a KN75, or just buy a used Garmin Sl30 which has a built in GS receiver, then remove the Mac 1700. I will need to buy a new KI 209 for ~ $1,000 (or similar indicator) whether I buy the used KN 75 to add to the Mac1700, or whether I remove the Mac1700 and replace it with a used Garmin SL30. My plane has the Approach Fast Stack System, so I am hoping the installation will not be all that complex either way, just new trays and cables to the Approach Pro-X HUB. I think the King KN75 GS receivers are pretty sturdy and they seem to be plentiful. I have space available under the nose cowling for the KN75.
I am not sure how the Mac 1700 (built on the KX175B) is with the number of COM frequencies we are to use now, but I haven't had any issues using it this past 3 months. I believe the Garmin SL 30 can drive the King KI209 indicator (they are compatible).
I would appreciate any advice.
Gomer

[Kristin Winter]

I may be wrong, but I thought the KI-209 had the built-in VOR/LOC converter and so does the SL30, which may mean that they are not compatible. The KI-206 does not have the converter and would be compatible with the SL30.

[Gomer Pound]

Hi Kristin, Thanks for the reply. The way I understand it the KI 209 has a VOR/LOC/Glideslope indicator with a built in "converter," but requires an external glideslope receiver, such as a KN 73/75 (from King website). I haven't read enough about them yet to know exactly what the "converter" does, but I think it is necessary for the instrument to display the GS bars correctly based on varying speed from what I can tell.

Also, I am going to look for the King KI 204 indicator instead of the King KI 209 because the 204 is TSO'd and has a rectilinear needle and optically coated glass instead of a plastic lens.The 204 also requires and external glideslope receiver.

Gomer

[Gomer Pound]

I took the plane to Avionics Place in Rockford, IL, where Geoffrey ran diagnostics on the KI214 on the ramp, then in the hangar. The 214's glide slope tested fine. The CDI had about 15 degrees error which he was able to adjust to zero error, so I am keeping the MAC/214 combo for now. The KCS55A's glide slope indicator was a bit sticky on testing. I probably don't see the sticking while flying because of vibration.I plan to remove it as well as the KG102 gyro in November during the annual and send to AeroLab Aviation in FL. I spoke with Bob Bramble, the owner. He is an ex-King employee who now specializes in HSI's. His shop is at Sarasota Avionics.
Geoffrey also did the update on my GNS480 that I ordered back in June ( I did not have time to have it installed until now). I dropped off the NOS L3 WX-500 stormscope I bought. He is going to test before installing at the annual. The service was excellent. Geoffrey was on the ramp with his equipment before I could get out of the airplane after I landed.

[Clarence Beintema]

Gomer,

You may want to check with www.kx170b.com they specialize in all things in the 170/175 series.

Clarence

[Gomer Pound]

Hi Clarence, Thanks for the link. The website says he will calibrate the 214 indicators, but if the indicator needs repair, they cannot be repaired.
Gomer