Wed, Sep 7 2005

After a lot of research, I bit the bullet and upgraded my KX170B to an
MX170c.  It was a direct slide in replacement, my KI-214 worked immediately.
The same evening I replaced it I tested the glideslope and it was right on
the money. The only thing I noted is the squelch preset and night dimming
preset were not adjusted to my liking.  But both were easily adjusted with
front screw adjustments and a jewelers screwdriver.

This Friday I'm heading over to the avionics shop to check the calibration
of my two vor's to make sure their in spec for IFR.

Got to say I love the flip-flops and it sure beat the alternatives from a
cost/installation stand-point. 


Thurs, Oct 13 2005 11:08 am

Bought one at OSH '99.  Carried it out to my plane in the North 40, slid the
old KX-170B out, slid the new MX-170 in, powered it up and made a log-book
entry.    Carried the old KX-170B to the dealer, who gave me cash on the
barrel head for it.   Good deal all around.

It was the best radio I've used yet.   Absolutely perfect operation, crystal
clear reception and transmission.  Only dumb part was the "frequency memory"
feature, which was completely unusable in anything but perfectly calm
conditions.  (You had to push two buttons exactly simultaneously, if I'm
remembering right, in order to access the stored frequencies.  Try doing
*that* in turbulence!) 



Tues, Oct 11 2005 11:04 pm

About $1500 and it slips into the existing tray.  The only complaints
we had were that the frequency-memory feature is complicated to use
and it's hard to remember the sequence of buttons.  Twice, it froze
until whoever was flying it at the time recycled the avionics power
bus.  This was a unit bought in, I think, 2001.  We never contacted
Michel because they don't have a Web presence.  (They do have a phone.
They're down around Phoenix -- Chandler, I think.)

We eventually redid the panel, replacing the MX170 with a KX125
because that gave us room for an old Apollo GPS that would work with
the STEC autopilot we were installing at the same time.  We moved the
Michel to our 1961 C172, which we were selling, figuring the new radio
was a deal sweetner. 

Wed, Oct 12 2005 12:05 am

My previous airplane had two MX-300's (the slide in replacement for the Cessna radio), and they worked
fine. I did have a problem with one of them once, and took it to their shop (I'm here in the Phoenix area
and their facility is at SDL) and they took care of it very quickly. This has been a few years, but at the
time, they had a flat rate for repairs - around $75 if I recall. But this would definitely be less convenient if
you have to ship it to them and wait for turnaround.



Tues, Oct 11 2005 11:53 pm

I used to have an aircraft with a TKM radio in it.  It quit receiving
and I took it to an avionics shop.  TKM would not provide any
documentation to the repair shop and said that the radio must be sent
to TKM.  TKM did not fix it the first time nor the second time but
finally after three tries with me paying the shipping and three months
down time it FINALLY came back from TKM working.  It was not
intermittent it was dead.  This is my experience yours may be
different.

Wed, Apr 30 2003

 > Remember that the MX170B, like the King it replaces, needs a processor
> for the VOR and G/S.  You can't just plug any indicator to it.  I
> think the King models you need are KN75 and KN73 (? I think).

There are two issues being conflated here I think.

One is, the King nav radios don't simply feed an analog signal into
their OBS, so yes, you can't use any indicator, you need a King
indicator.

However, you don't need an additional processor for VOR and LOC
signals.  The radio and the indicator suffice.

For a glideslope, you need a glideslope receiver.  You're right,
the KN75 and KN73 are appropriate models. 



Tues, Apr 29 2003

 > Has anyone had experience with the MX170B? Good, bad whatever, I'll like to
> hear your thoughts.

We have had one for 5 years.

It went back to the factory once, under warranty, after an intermittant
problem w/ frequency switching which they couldn't reproduce.  I asked
what they thought would cause the problem, they told me, I asked them
to replace that part, they did, no problems since (3 yrs ago)

Plusses vs KX170B:
   flip-flop and freq. memory nice
   good clarity per radio checks
   squelch adjust accessible from front so you don't have to
   pull the radio out of the stack to fiddle
   doesn't produce as much heat as KX
   cost-effective slide-in replacement for existing installation
Minuses:
   said (by avionics guys who make no money from 'em) to be
        less robust and reliable
   not as good range as KX170B (lower power)
   if there are problems in existing wiring harness/antenna
        they will migrate to new radio
   must be serviced at factory (they are reasonable)

If you are installing a new radio, I think there are others which
might be a better choice.  Because it is factory-service only,
avionics installers don't like them; you might get caught in a
finger-point fest between the installer and the factory "the
radio is fine, the installation is wrong" "the installation is
just fine, it's the #@!! radio" 


Wed, Oct 8 2003


> My two KX 170B NavComs are getting a bit tired.  The tuning gears have been
> replaced, and after several years are now getting really stiff and hard to
> turn again.  Apart from the mechanical parts, the radios both work just
> fine.

> I am looking at three alternatives; having them repaired again, getting the
> MAC 1700VTX conversion, or replacing them with TKM MX-170B units.  The
> conmversion and the TKM units seem to be about the same price.

> What is the collective wisdom of this newsgroup?  Does anyone have direct
> experience with both the MAC and TKM products?

Actually, since your 170B's are still worth $300+ each on eBay (and
that's being conservative - I've seen them go for $400+) you better be
saving at least that much by going with the TKM over the MAC.  And
then there's the downtime of having your radios worked on.  And the
fact is, the electronics are still old.  I would avoid the MAC.  BTW,
the MAC conversion was made by McCoy, and they are out of business.  I
understand someone else picked up the support.

Realistically, if the only problem is that the mechanical parts are
getting stiff and hard to turn, a good cleaning may solve your
problems.

I used to have a MAC and a KX-175B in my plane.  Once I had an
overvolt condition due to a short in the field line.  The KX-175B was
fine.  The MAC could still transmit and receive, but the digital front
end got fried beyond repair, so no display.  I now have a 170B where
the MAC used to live. 
 

Tues, Nov 30 1999

I've had an MX-11 for almost 8 years and it has worked flawlessly, up
to now.  Gotta send it in for a little audio work this week, but it's
a neat piece of gear.  Haven't seen the MX170 in operation, but if it
works as well as the MX-11, I'd recommend it. 


Tues, Nov 30 1999

I replaced an old Narco 110 with a TKM MX-11 several years ago.  I was concerned
about the TKM products myself since I was unfamiliar with them.  I can report
that as of today, the TKM as been a great radio.  I receive comments all the
time how nice my radio sounds.  The reception is great also, and I fly in an
open cockpit biplane.  If I remember correctly, the TKM also puts out 8 watts of
power that really seems to make a difference.  As an affordable way to upgrade
an existing Comm, the TKM is a nice way to go.

Sun, Dec 5 1999

I have had a TKM MX-170B in my piper arrow for about 6 years and it has
worked flawlessly. I don't know why the price difference, except that
since TKM is a smaller manufacturer the only way it can compete with
Bendix/King and others is to reduce their price. The only thing I don't
like about it is that the knobs are not strong enough to grab to pull
the radio out of its slot (you have to grab it by the edges of the
faceplate instead). I think it's probably small details like this that
make up the cost difference. Electronically, it has performed
flawlessly, probably due to simplicity in function and operation. It's a
good low-cost alternative when replacing a KX-170B in your aircraft.
They don't have any regional repair centers, so you must send it back to
the factory for any repairs, but the labor rate is a flat rate and the
turnaround time at the factory is under 3 days, so it's not a bad deal. 

Tues, Jun 7 1994

    I recently replaced my old Cessna NAV/COM 300  with the MX300V  radio. I
 think it's a winner.  Installation was as simple as removing the old radio
from the tray and slipping in the new one. Because my radio was an old 1967
vintage tube-type I also needed the adapter tray. So far I am very pleased
with it. The built-in CDI is a nice touch and is VERY accurate, but does
take some getting familiar with. I haven't had it installed long enough to
judge its reliabilty,  but I understand TKM is very customer oriented and
with the 3 year warranty stands behind their products.          
    Narco is getting a lot of bad press on this forum and maybe deserved.
But in their defense I must add that I recently had to have my Narco
transponder repaired and had no trouble finding a master repair shop to do
the work. Total downtime including UPS shipping was 5 days.   


Wed, Apr 28 1999


One thing not mentioned is the elimination of a potential future
problem.  One you might "accidentely" cause yourself.

On the KX-170x there is a locking cam used to secure the radio in the
panel.  When removing the radio turn it ONLY 1/4 of a turn. DO NOT
turn it 1/2 turn, 3/4 or one full turn!

The channel select switch is located directly above this cam.  If you
go past the 1/4 limit and apply any force at all the next sound you
hear is the crunching of the wafer switch as it goes bye-bye.

Cost for the part was $178.00, labor $275.00.

You completely eliminate this problem with either the MX-170B or the
McCoy conversion.  Then again, if you have this problem now's the time
to get either.  For my $.02 cents worth the McCoy seems to offer just
slightly more doo-dads up front, but the Michel warranty and repair
cost are a better long term value. 



Mon, Apr 19 1999


> I just came back from Sun'n'Fun and was planning to buy  a replacement Radio
> for my KX170B. My plan was to buy a Michel TKM MX-170B and was told by most
> of the dealers in the show, that this radio is absolute garbage and was
> advised not to buy it. What is the experience of the people who own these
> radios, and is the MAC1700 face plate to KX170B a better alternative?

I have an MX170B, purchased as a slide-in replacement for a KX170A.
We are happy with it.  We had one problem which proved to be in the
existing KI201 OBS, not in the nav radio. Radio checks, we are told
we are clearer on it than on the KX170B which is still in our panel.
Transmitting on the MX170B does not cause interference with the GPS,
unlike our KX170B (and I've heard KX155s are also notorious for this).

I too was told "it is junk" by local avionics shops who don't sell it.
Let's see, it is a slide-in replacement I can do myself with an A&P
signoff and update to W&B, it is factory-only repair with a 2 year
warranty, there is very little if any profit to the avionics shop on
this radio vs. installing KX155 nav/com, could that have anything do
do with their opinion?  Hmmmmmmmmmm. 


Wed, Feb 14 1996


Re: TKM MX-300 vs Narco Mk12D as ARC replacements

After seeing several TKMs in other Cardinals, I bought one and am very happy
with it.  TKM comes with a warranty (2 yr?) and repairs are fixed $40, even
after the warranty according to the one owner I met who ever had one that
needed repair.  Compare that to Narco!

TKM radios come in tan or black faceplates, your choice.

Seems to me the alterative is a complete new King KX-155/KI-209.  My radio
shop bench-tested them, and said the TKM has slightly better transmit
modulation index and power output, and same sensitivity and audio quality.

You can still buy yellow-tagged solid-state ARC glide slope rec'r for $220,
and indicators for $250 and up.  As long as this is true, why buy a new King?

For example, I just bought a new ARC IN-381AC rectilinear indicator, with
autocentering servo and LOC and BC lights, for $500.  With the TKM radio,
its nicer than a new King, and 1/3 the price.  That works for me!