Shameless request for King radio Tech Support

Greetings gang.. As the title suggests, this is a request for knowledge
and assistance, and in much of the situation I am wanting to verify what
I THINK I have gleamed from pertinent technical manuals.

The background:
Partner in an experimental (but posting here, because what I am seeking
is not exclusively from that crowd), building the panel from auction
radios (very patiently, I might add, waiting over time for the "right"
deal to pop up) and have come to possess the following:

1) KX-175B 720 ch com,
2) KY-195B 720 ch com (essentially a com-com that fits a 170-175 tray,
same pinouts - think of it as a mechanical flip-flop com)
3) A KLN-89B IFR GPS (terminal, enroute and non-precision approach capable)
4) KN-75 Glideslope Rec
5) AT-50A Transponder

I have since acquired pinouts for all, and the install manuals for the
175 and the 89B.

My background: Grew up around aviation, got my ticket 5ish years ago,
450 hrs, instrument trained but not rated (gee..sounds a lot like JFK..
shudder). College was heavy in the natural and applied sciences, and
I've got a better than novice grasp of electronics and wiring. I've got
fairly heavy experience using the King line of GPS and am comfortable
with their "architecture" and organization (Garmin is great, i just dont
have 200 hours behind their stuff).

What I DONT have is education, training and textbooks appropriate for
avionics technicians. I've got novice to above novice ability regarding
this, but consider myself a quick learner and critical thinker.

So.. things I want to check/verify:

1) The KX-175B TSO is still acceptable for use in the US, and uses 720
channels. It does not contain a glideslope reciever nor a "converter".

2) Has anyone out there encountered areas that make use of the
additional 40 channels (the 760 chan radios) in the continental US below
18,000 feet. Are these tower? Approach? Weather? Center?

3) The 175B, by not having a converter, requires either an indicator
that has an integral one, such as the KI 201,204,208,209 or 214... or
requires an external converter such as the KN-72. The 208/9A series, I
belive, has the converter but also can be driven by GPS. The GPS is
otherwise incompatible with indicators that have the internal converter
(except for the 208A and 209A).

4) If paired with the KN-72, then the 175B can drive any of the other
indicators, including mid continent, collins, stec, ARC and the
applicable non-converter king products. The GPS can drive these
indicators in a stand-alone setting. This is a key item for me that I am
not sure of, as I am currently shopping for indicators, and the new cost
of some of them can exceed what I've spent on panel ($1600) so far.

5) What is the name for the scheme that the KX-175B uses to drive the
glideslope reciever - 10 or more wires that are each associated with a
specific MHZ or KHZ range? I've seen 2x5 arinc, slip code and other
terms used and havent specifically associated them with what they are
supposed to mean.

6) What is name of the scheme that the KX 175B uses to drive a DME
reciever, keeping in mind the same comments as above. This appears to
be different that the glideslope wiring scheme, with 8 wires that appear
to be some sort of parralel binary scheme.

7) As of Spring 2004, I was under the impression that installation of an
IFR approved GPS was now considered a minor alteration, so that in
certified aircraft it could be accomplished with a logbook entry. If not
otherwise prohibited by my experimental operating limitations, is there
any reason that I could not install the 89B (with the proper remote
accessories and up to date database) and use it in a /G role. Anyone out
there have experience with this issue in a experimental-amatuer built
aircraft?

8) Unless there has been a change, my understanding is that an IFR GPS
requires a remote annunciator in the primary scan of the pilot, and a
separate/remote CDI that is "in the scan" as well. Any experience in
using the King 89B with a NON-KING CDI out there (compatibility is what
Im looking for). How many out there have the GPS use its own CDI? or
share it with another Nav?

9) How many folks out there who've added GPS's to their panel have "the
works" done.. interface it to the altitude encoder, air data unit, your
fuel manager or the OBS resolver on your CDI. I've flown behind many
rental planes with King GPS in them, that had none of this done, but
flew in ONE very nice A36 that came from the factory with the GPS
integrated nicely into the stack. Folks that have done this interface,
did you have interference with the xpnder that was also getting data
from the encoder? Did you have to use diodes or a second encoder or
leave it unconnected?


10) Back to remote switching.. I've only used the Mid Continent MD41
series for remote annunciation and switching. Anyone have favorable (or
un) experience with competing brands and willing to share? Seems that
used 14V varieties are scarce regardless of the make.

11) I started wiring both of the radio trays (175 and 195) for eventual
upgrade to dual nav-com, glideslope and DME capability before I came to
possess the GPS. How many out there have both DME and GPS, and use their
DME regularly despite GPS being an acceptable substitute?

12) Panel space considerations will likely rule out a panel mount DME if
ever acquired, until or unless the 175 and 196 are replaced by slimline
radios down the road. What is the appropriate designation for a King
remote mount DME (and indicator) that would fit in this situation, and
is the remote unit fairly light/compact or is it essentially a heavy
transplant from a bizjet? (truth is, will likely not use it, but I want
to keep the options and eyes open if it comes along).

13) With upgrades in mind, who all is flying behind a KLN-94 (a direct
slide in replacement for the 89B) and whats your feedback on it, as
compared to the KLN 89 and 90 series GPS.

14) Back to indicators... do all of the CDI's out there have OBS
resolver outputs on them, or only specific brands? or only specific
models of said brands? I am understand OBS resolvers to be the the
ability of the GPS to read what radial the OBS is set to.

15) Thinking ahead for when I get an AP. If I understand properly, the
nav radio's (or GPS) drive the indicators, and the indicators drive the
Autopilot with left/right info derived from the nav source. So, in
theory, if the above is correct, when adding an autopilot that can take
steering commands from the nav suite, its usually just a matter of
adding the wires to the CDI (and switching, for multiple sources).

Ok.. that is about as much as I can think to ask about for the moment.

Thank you for your patience.

If Im wrong about something, I know without a shadow of a doubt this
group will let me know. This is actually one of the harder tasks I've
come across in partnering in this aircraft. While there are all sorts of
DIY things that pilots can do from a mechanical/maintenance/building
standpoint, there is not much Do-it-yourself stuff out there for
avionics. I even obtained a fairly recently published book that claimed
to be aimed at people like me - doing our own installs, but there wasnt
much substance there except a rehash of good workmanship techniques
(grounding, shielding, etc) and basic theory of operation. I dont even
think I SAW the words gray code, slip code, 2x5 arinc, etc...let alone
anything technical.

Seeking Peer review,
Dave

List of acceptable radios by FCC
http://wireless.fcc.gov/aviation/goodlst.html

"Dave S" wrote in message
nk.net...
7) As of Spring 2004, I was under the impression that installation of an
IFR approved GPS was now considered a minor alteration, so that in
certified aircraft it could be accomplished with a logbook entry. If not
otherwise prohibited by my experimental operating limitations, is there
any reason that I could not install the 89B (with the proper remote
accessories and up to date database) and use it in a /G role. Anyone out
there have experience with this issue in a experimental-amatuer built
aircraft?


It is my understanding that even an ex-am built aircraft that to be IFR
legal the installation of the GPS has to be done to the TSO order by a
"qualified" installer.

I thought this was all a little strange because while I could build a
NAV/Com and glideslope receiver out of coconuts and bailing wire and install
it and fly IFR with it. I can't order a brand new Garmin 430, install it and
legally fly IFR with it.

Impressive amount of pitfalls you've discovered already. I'd say you've got
the right mindset to make this go. I did basically the same thing, although it was on
a certified aircraft (PA-28-180). I had to write up all of the approved data (AC43
for wire types, sizes, gauges, and install manuals consulted, etc) and get a field
approval through the FSDO. My mechanic helped with all the paperwork and approved the
installation. Comments below:

: 1) KX-175B 720 ch com,
: 2) KY-195B 720 ch com (essentially a com-com that fits a 170-175 tray,
: same pinouts - think of it as a mechanical flip-flop com)
: 3) A KLN-89B IFR GPS (terminal, enroute and non-precision approach capable)
: 4) KN-75 Glideslope Rec
: 5) AT-50A Transponder

: I have since acquired pinouts for all, and the install manuals for the
: 175 and the 89B.

You may need to get install manuals for some of them. Try to make friends by
ordering some components from avionics places... you may need to order connectors, or
pins or something.

: What I DONT have is education, training and textbooks appropriate for
: avionics technicians. I've got novice to above novice ability regarding
: this, but consider myself a quick learner and critical thinker.

: So.. things I want to check/verify:

: 1) The KX-175B TSO is still acceptable for use in the US, and uses 720
: channels. It does not contain a glideslope reciever nor a "converter".

True.

: 3) The 175B, by not having a converter, requires either an indicator
: that has an integral one, such as the KI 201,204,208,209 or 214... or
: requires an external converter such as the KN-72. The 208/9A series, I
: belive, has the converter but also can be driven by GPS. The GPS is
: otherwise incompatible with indicators that have the internal converter
: (except for the 208A and 209A).

I think I recall hearing that on the 208/209. You could also go with a 206
or the old KNI-520 for the GPS and get the external converter for it for the 175.

: 4) If paired with the KN-72, then the 175B can drive any of the other
: indicators, including mid continent, collins, stec, ARC and the
: applicable non-converter king products. The GPS can drive these
: indicators in a stand-alone setting. This is a key item for me that I am
: not sure of, as I am currently shopping for indicators, and the new cost
: of some of them can exceed what I've spent on panel ($1600) so far.

We got almost all of our stuff via ebay.

: 5) What is the name for the scheme that the KX-175B uses to drive the
: glideslope reciever - 10 or more wires that are each associated with a
: specific MHZ or KHZ range? I've seen 2x5 arinc, slip code and other
: terms used and havent specifically associated them with what they are
: supposed to mean.

: 6) What is name of the scheme that the KX 175B uses to drive a DME
: reciever, keeping in mind the same comments as above. This appears to
: be different that the glideslope wiring scheme, with 8 wires that appear
: to be some sort of parralel binary scheme.

Don't know about these specifics, but I would think that there's only one
set... I don't know if there are isolation issues (diodes, current draw, etc) like
transponders/encoders can have.

: 9) How many folks out there who've added GPS's to their panel have "the
: works" done.. interface it to the altitude encoder, air data unit, your
: fuel manager or the OBS resolver on your CDI. I've flown behind many
: rental planes with King GPS in them, that had none of this done, but
: flew in ONE very nice A36 that came from the factory with the GPS
: integrated nicely into the stack. Folks that have done this interface,
: did you have interference with the xpnder that was also getting data
: from the encoder? Did you have to use diodes or a second encoder or
: leave it unconnected?

Our setup did not include an IFR-certified GPS... rather a VFR GPS/COM
(KLX-135). Since it wasn't that big of a deal, I wired up the altitude encoder for
the transponder to it as well. I did need to add the diodes. Also, some encoders
(Narco in particular) are bad about the low-voltage logic level. In my mechanic's
plane (I did the wiring to install his IFR GPS in his personal plane), the addition of
diodes caused the logic to be intermittent on the GPS. The additional voltage drop of
Si diodes was problematic... a logic '0' wasn't low enough to be a '0' all the time.
A different encoder and unusual diodes worked.

: 11) I started wiring both of the radio trays (175 and 195) for eventual
: upgrade to dual nav-com, glideslope and DME capability before I came to
: possess the GPS. How many out there have both DME and GPS, and use their
: DME regularly despite GPS being an acceptable substitute?

I've got a KNS-80 VOR/LOC/GS/DME/RNAV installed and I use it all the time. My
primary "Direct-To" instrument is the GPS, but I cross-check on the VOR and DME all
the time. Much quicker to dial up 116.8 on a DME than twirling through 'P-S-K' on a
friggin' GPS. I don't know if the additional utility gained out of a *pure* DME would
be worth the expense, weight, or complexity in channeling it up with the NAV, though.

: 12) Panel space considerations will likely rule out a panel mount DME if
: ever acquired, until or unless the 175 and 196 are replaced by slimline
: radios down the road. What is the appropriate designation for a King
: remote mount DME (and indicator) that would fit in this situation, and
: is the remote unit fairly light/compact or is it essentially a heavy
: transplant from a bizjet? (truth is, will likely not use it, but I want
: to keep the options and eyes open if it comes along).

Since it sounds like you've got all your equipment already, you'll probably
want to go with what you've got. I highly recommend the KNS-80 for its functionality
and cheapness used these days... Lots of bang for the buck. Ours is paired with a
thin KY-197 COM for a "super nav-com" combo... Also, the same converterless head
will work with the GPS. For the record as well, I believe the KX-165 also works with
a converterless head.

: 13) With upgrades in mind, who all is flying behind a KLN-94 (a direct
: slide in replacement for the 89B) and whats your feedback on it, as
: compared to the KLN 89 and 90 series GPS.

Never flown IFR with an IFR GPS.

: 14) Back to indicators... do all of the CDI's out there have OBS
: resolver outputs on them, or only specific brands? or only specific
: models of said brands? I am understand OBS resolvers to be the the
: ability of the GPS to read what radial the OBS is set to.

I'm not completely sure, but I think there are a couple of newer kinds. We
ended up with a KNI-520 on our KNS-80, but the KI-206 would also have worked AIUI.

: 15) Thinking ahead for when I get an AP. If I understand properly, the
: nav radio's (or GPS) drive the indicators, and the indicators drive the
: Autopilot with left/right info derived from the nav source. So, in
: theory, if the above is correct, when adding an autopilot that can take
: steering commands from the nav suite, its usually just a matter of
: adding the wires to the CDI (and switching, for multiple sources).

I'm not too familiar. I think when I was helping my mechanic rewire his
that's all it used.

: If Im wrong about something, I know without a shadow of a doubt this
: group will let me know. This is actually one of the harder tasks I've
: come across in partnering in this aircraft. While there are all sorts of
: DIY things that pilots can do from a mechanical/maintenance/building
: standpoint, there is not much Do-it-yourself stuff out there for
: avionics. I even obtained a fairly recently published book that claimed
: to be aimed at people like me - doing our own installs, but there wasnt
: much substance there except a rehash of good workmanship techniques
: (grounding, shielding, etc) and basic theory of operation. I dont even
: think I SAW the words gray code, slip code, 2x5 arinc, etc...let alone
: anything technical.

Tell me about it. Getting the official information is the most difficult part
for DIY. Once you do, it's not too difficult. Very careful practices need to be used
for materials, bundling, stress relief, support, chafe prevention, soldering, head
shrinking, etc to do a good aviation-worthy reliable job.

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

wrote:
Tell me about it. Getting the official information is the most difficult part
for DIY. Once you do, it's not too difficult. Very careful practices need to be used
for materials, bundling, stress relief, support, chafe prevention, soldering, head
shrinking, etc to do a good aviation-worthy reliable job.

Are you saying you'd have to be crazy to try this yourself?!

(kidding... I assume you meant "heat" shrinking)

-R

Rob wrote:
wrote:

Tell me about it. Getting the official information is the most difficult part
for DIY. Once you do, it's not too difficult. Very careful practices need to be used
for materials, bundling, stress relief, support, chafe prevention, soldering, head
shrinking, etc to do a good aviation-worthy reliable job.


Are you saying you'd have to be crazy to try this yourself?!

(kidding... I assume you meant "heat" shrinking)

-R


No.. i think a small amount of head shrinking and other black art forms
are a key part to making all this work.

Thanks for the replies so far.. in here and in private.

Dave

So.. things I've learned in the past 24 hours..

Hooking up the 89B to all the goodies is where it can get interesting.
There are stators and rotors and other thingywhatzits inside the OBS
mechanism of a CDI that can be used to feed info back to the GPS (or
other device like a KX165 or KNS80). In the case of the GPS, it lets
your GPS box know what your OBS is set on.

But.. it may be 30hz 1 phase current or it may be 450 hz 1 phase current
that drives it. King makes both, by the way. And.. something I always
suspected but didnt know until now.. the old stuff was all about
proprietary systems and "use only our stuff" modus operandi.. The worst
surviving offender that I can tell is King (erm.. Honeywell).. but even
that is old news.. the semi new stuff all uses the ARINC standard
format.. and the new new stuff uses RS-232 serial busses. What those
technically entail.. beats me.. but they use it.

Before i realized that the avionics makers of old REALLY REALLY didnt
like "cross-breeding" their stuff with competitors stuff, I found and
bid on an ARC/SPERRY new-old-stock IN-381A vor/loc/gs indicator with
integral converter.. thought.. ok.. this can work with the king.. now im
not so sure.. at least not without some additional information. I want
to say the King drives the indicator with 500 mv and the sperry
indicator is used to being driven at 150 mv. Something to follow up on
lest I let the smoke out of the indicator that I know is dying to
escape. If I cant use it there, I'd like to see if the GPS can drive
it.. maybe maybe not. I think it should, tho, even with the converter,
since it is also a standard ARINC CDI. IF perchance BOTH radios can use
the indicator, then by golly, im getting a second one so at least stuff
PRETENDS to match in a few places.

There truly isnt much out there in the general public about techical
aspects of DIY avionics. Its almost easier to get secrets from a 20th
degree mason than it is to get free tech support or even access to the
manuals to self teach. I understand why: keep the knowledge within the
realm of the dealers and you HAVE to use the dealers/avionics shops to
get the job done.. but I dont have to like it.

So far, the greatest help has been a few key pinouts unrelated to the
89B that show a given other GPS and it interfacing with umpteen other
indicators on a line by line, wire by wire basis. Makes it easy to
reverse engineer what I plan/hope to do.

With regards to the GPS antenna.. so far, everything has been embedded
in the fuselage (as is typical with homebuilt composite types).. well
thats all but done. The primary builder/glassman would not care for a
bump on the roof from the GPS ant, so to verify with the masses, a GPS
antenna can also be completely internal on an epoxy/fiberglass
structure? Im thinkin on the top of the dash "looking" out the window,
even though the window itself is allegedly no less transparent than
fiberglass. The install manual discusses avoidance of the windshield due
to "streaming".. is this solely a metal/conductive a/c event or
something a plastic plane guy should worry about?

So.. if I have a dedicated indicator for the GPS, for an IFR install,
its all about having a few annunciator lights and two switches (OBS/LEG)
and (ARM/Disarm). Maybe I should just home brew the whole thing in
protest, since I wouldnt need a 20+ pin switching relay that retails for
1 AMU plus.

And.. just to let it be known, im not planning on building my coffin.
The experimental I'm involved in isnt to be a hard IFR plane, but then
many light GA planes are barely so, but its still going to be nice to
get in and out of places safely where the visibility isnt THAT good, or
the clouds arent THAT high, and give me a cost effective platform to
finish and maintain that rating in to boot.

Dave

"Dave S" wrote in message ink.net...
Snip
There truly isnt much out there in the general public about techical aspects of DIY avionics. Its almost easier to
get secrets from a 20th degree mason than it is to get free tech support or even access to the manuals to self
teach. I understand why: keep the knowledge within the realm of the dealers and you HAVE to use the
dealers/avionics shops to get the job done.. but I dont have to like it.
snip

Dave, I haven't been following this thread and I know zilch about avionics. However, I do know that there is an
avionics list he
http://www.matronics.com/ called the AeroElictric list that many homebuilders use for electrical / avionics type
help. You might try asking over there for help if you haven't already done so.

Joe



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