----------------------------------------------------------
                           AeroElectric-List Digest Archive
                                      ---
                     Total Messages Posted Thu 10/02/03: 19
           ----------------------------------------------------------
 
 
Today's Message Index:
----------------------
 
     1. 06:29 AM - relay diagram for Microair PTT  (Sigma Eta Aero)
     2. 07:47 AM - Re: Fast-ons  (Robert L. Nuckolls, III)
     3. 08:08 AM - Re: Alternator speeds and belt tensions.  (Robert L. Nuckolls, III)
     4. 08:18 AM - Re: Use of individual wires from a Mil-Spec  (Robert L. Nuckolls, III)
     5. 08:20 AM - Re: relay diagram for Microair PTT  (Robert L. Nuckolls, III)
     6. 08:45 AM - Re: Dielectric grease recommendations  (Robert L. Nuckolls, III)
     7. 09:37 AM - Re: Re: Alternator speeds and belt tensions.  (Jim Jewell)
     8. 10:33 AM - Re: relay diagram for Microair PTT  (Sigma Eta Aero)
     9. 10:57 AM - GPS-35 / Transponder / Autopilot  (Phil Birkelbach)
    10. 12:57 PM - Re: relay diagram for Microair PTT  (Robert L. Nuckolls, III)
    11. 01:52 PM - Re: relay diagram for Microair PTT  (Sigma Eta Aero)
    12. 02:15 PM - Re: Use of individual wires from a Mil-Spec  (Charlie Kuss)
    13. 02:15 PM - Re: Low voltage warning circuit  (Robert L. Nuckolls, III)
    14. 02:39 PM - Re: relay diagram for Microair PTT  (RSwanson)
    15. 02:57 PM - Re: Dielectric grease recommendations   (Eric M. Jones)
    16. 05:54 PM - Re: relay diagram for Microair PTT  (Robert L. Nuckolls, III)
    17. 06:22 PM - Re: relay diagram for Microair PTT  (Sigma Eta Aero)
    18. 07:13 PM - Re: Re: Alternator speeds and belt tensions.  (Richard Sipp)
    19. 08:50 PM - Re: Re: Low voltage warning circuit  (Steven DiNieri)
 
 
 
________________________________  Message 1  _____________________________________


Time: 06:29:58 AM PST US
From: Sigma Eta Aero <sigmatero@yahoo.com>
Subject: AeroElectric-List: relay diagram for Microair PTT

--> AeroElectric-List message posted by: Sigma Eta Aero <sigmatero@yahoo.com>

--0-1662827501-1065101367=:90978


How exactly are the relays wired on the Microair PTTs?  The schematic that Microair
supplies is a little confusing for me.  

I don't like always having it hot.  When the relays are installed how does it decide
who gets to transmit if both switches are pushed (whoever is first? It becomes
hot again so both can talk at the same time?) 

Which relays to use (prefereably something small and light and cheap)?

Thanks!

Joa


---------------------------------
--0-1662827501-1065101367=:90978

<DIV>
<TABLE cellSpacing=0 cellPadding=0 width="100%" border=0 ?>
<TBODY>
<TR>
<TD>
<P>How exactly are the relays wired on the Microair PTTs?&nbsp; The schematic that
Microair supplies is a little confusing for me.&nbsp; </P>
<P>I don't like always having it hot.&nbsp; When the relays are installed how does
it decide who gets to transmit if both switches are pushed (whoever is first?&nbsp;It
becomes hot again so both can talk at the same time?) </P>
<P>Which relays to use (prefereably something small and light and cheap)?</P>
<P>Thanks!</P>
<P>Joa</P></TD></TR></TBODY></TABLE></DIV><p><hr SIZE=1>
--0-1662827501-1065101367=:90978--






________________________________  Message 2  _____________________________________


Time: 07:47:31 AM PST US
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Fast-ons

--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>

At 06:16 AM 10/2/2003 +0200, you wrote:
>--> AeroElectric-List message posted by: "John F. Herminghaus" 
><catignano@tele2.it>
>
>Bob,
>
>Just out of curiosity, why doesn't B&C use fast-ons on their voltage
>regulators?
>
>John Herminghaus

   The regulator was designed in the year 8 BFO . . . (before fast ons).
   We were not even considering their suitability and utility in system
   fabrication at the time. We wrestled with whether or not to use
   terminal screws or some kind of connector (95% of my customers for
   certified product shun terminal strips . . . too easy to mess up
   wire placement in the field).  Terminal strips were chosen for
   cost effectiveness. Now that these regulators are part of STC'd
   kits, they are for all practical purposes, cast in stone. If
   I do any new designs for OBAM aircraft, they will be fitted with
   a connector.

   Bob . . .






________________________________  Message 3  _____________________________________


Time: 08:08:11 AM PST US
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: AeroElectric-List: Re: Alternator speeds and belt tensions.

--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>

At 06:27 PM 10/1/2003 -0700, you wrote:
>--> AeroElectric-List message posted by: "Jim Jewell" <jjewell@telus.net>
>
>Hi "jerb",
>
>The last I heard spinning an alternator at 8000 rpm. is well within any
>usefull limitations on it's bearing life.

    B&C alternators have racked up tens of thousands of flight
    hours running well over 10KRPM with great success.

>As far as belt friction and adverse heat generation are conserned the older
>style V-belts are happier on larger pulleys. I expect this is a big part of
>why the auto industry went over to the Micro-V type belts.
>Depending on the size of the larger alternator pulley you choose you might
>find that the alternator output at idle is adversely effected.

    agree

>In the past more than one builder has encountered the need to add a blister
>to the cowl to clear the alternator pulley. The likelihood of this occurring
>is increased when a larger diameter pulley is installed.

    correct


>I in fact have a 3.5" pulley on my O360. this pulley clears the cowling by
>about 1/4" and I might have to consider reducing it's size for cowling
>clearance reasons.
>The engine came with accessories and the "starter ring" had been modified to
>utilize a Gates Micro-V belt that drives the alternator.
>He also made the 3.5" pulley It looks to me the fellow that made the pulley
>modifications did a great job and I will go with his idea until testing and
>actual use cause a change of course.

    that was a LOT of trouble and expense for nearly
    immeasurable benefit . . .


>I will certainly be happy to hear from a qualified person if what I have had
>quoted to me as safe alternator RPM. limitations needs to be brought up to
>speed (;}.
>
>I think a look in the archives will show that this has been hashed out some
>before.
>Try searching the archives wit (alternator rpm) or (alternator speed).


    Someone asked the question a few days ago, "What is the method
    for PROPER tightening of the alternator belt." A fair question
    since I've used the phrase many times. I and folks at B&C have
    been digging through the engineering literature on belts. If one
    wishes to install a belt for a particular tension, there are
    many non-cheap instruments you can purchase to actually measure
    and thus facilitate adjustment of belt tension.

    Okay, how do we pick a PROPER tension and can it be done without
    relying on expensive and seldom used instrumentation. Further,
    in light of more than half a century of "stick the crowbar in there,
    stretch 'er tighter than hell and cinch it down" techniques
    used in FBO and OBAM aircraft shops alike, belt life has not
    bubbled up to the top of our most pressing maintenance problems.

    After several days of picking though the sparse data, I'm
    about to conclude that actual tension settings for any
    particular application are empirically derived by the
    system engineer, not the belt engineer. Belts are loosely
    spec'd for horsepower ratings assuming a certain RPM (usually
    1750 - common motor output speed for many industrial situations)
    on the smallest pulley . . . which has nothing in common
    with the way we use the belts on airplanes.

    Intuitively, a belt running too tight is overstressed and
    life is reduced while bearing loads are excessive and
    reduces life of those components as well. A belt too loose
    slips, wears rapidly and prevents the alternator from
    running at max performance.  The range of tension values
    between too tight and too loose is huge. Obviously, from
    the pilot's perspective, the best thing is to err on the
    side of too tight and watch the belt for service life issues
    on the ground instead of discovering them in the air.

    Given our knowledge of decades of service history watching
    quality (Gates) belts run quality (ND) alternators, the
    loosely defined tightening technique defined above seems
    quite adequate. Every time I fly, fingers run over the
    surface of the belt looking for any signs of frayed edges
    and eyes look for signs of overheat-polish on belt sides.
    A tug on the belt confirms that it still "cinched down
    tight."

    I've never had to abort a mission due to discovery of
    a questionable alternator belt. Sooo . . . if it were
    my airplane, (and given the small cost of a belt compared
    to other costs of owning an airplane) I'd continue to
    do the crowbar operation for tightening and put a new
    belt on the a new battery every year. Both of these
    items will be at the bottom of the list for flight
    safety and/or maintenance concerns.

    Bob . . .






________________________________  Message 4  _____________________________________


Time: 08:18:52 AM PST US
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Use of individual wires from a Mil-Spec
  C-27500 cable

--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>

At 11:11 PM 10/1/2003 -0400, you wrote:
>--> AeroElectric-List message posted by: Charlie Kuss <chaskuss@bellsouth.net>
>
>Bob & Listers,
>  I was given a large quantity of Mil Spec Aviation wiring from a friend. 
> Some of this wire was 22 & 20 gauge C-27500 shielded 2 & 3 wire cable. 
> Some of this cable had been stripped of it's outer sheath and shielding. 
> This cable has color coded wires inside (red, blue & yellow). Are these 
> individual wires OK to use on my RV-8A project? It appears that the 
> insulation is slightly thinner on these wires as compared to individual 
> Mil 22759/16 wires. I'd like to use this wire, but I want to make sure 
> that I am not "cutting corners" in doing so. Opinions please.
>Charlie Kuss
>RV-8A  going cross eyed looking at wiring schematics
>SE Florida

   Mil-C-27500 is an ASSEMBLY specification for bringing a variety
   of materials (wires, shielding and outer jackets) together into
   bundles of wire that may be shielded. See:

   http://www.awcwire.com/pdf/CT-G4-M27500.pdf

   Given the relatively modern incarnation of this specification
   it is unlikely that anything you find assembled under it
   will be unsuited for use in your airplane. I'd say, "drive
   on and let not your heart be troubled."

   Bob . . .






________________________________  Message 5  _____________________________________


Time: 08:20:25 AM PST US
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: relay diagram for Microair PTT

--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>

At 06:29 AM 10/2/2003 -0700, you wrote:
>--> AeroElectric-List message posted by: Sigma Eta Aero <sigmatero@yahoo.com>
>
>--0-1662827501-1065101367=:90978
>
>
>How exactly are the relays wired on the Microair PTTs?  The schematic that 
>Microair supplies is a little confusing for me.
>
>I don't like always having it hot.  When the relays are installed how does 
>it decide who gets to transmit if both switches are pushed (whoever is 
>first? It becomes hot again so both can talk at the same time?)
>
>Which relays to use (prefereably something small and light and cheap)?
>
>Thanks!
>
>Joa

     I'm not familiar with any schematics provided by
     Microair that incorporate relays. Can you point me to
     an internet resource where I can find the drawing
     in question?

     Bob . . .






________________________________  Message 6  _____________________________________


Time: 08:45:30 AM PST US
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Dielectric grease recommendations

--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>

At 04:11 PM 9/28/2003 -0400, you wrote:
>--> AeroElectric-List message posted by: Gkb5577@aol.com
>
>I'm new to the forum.  I just got some dielectric grease off Ebay--3 tubes (
>big ones) for about $20.  I'm curious too  can bearing grease work?  The idea
>must have started some time ago with an old-timer and I JUST BET that the 
>type
>actually isn't all that important.  (?????)  Geoff

   If one is pre-disposed to use guckums to enhance the performance
   of a connection and there is a rational justification for
   them, probably any grease would add some level of enhancement.
   Having said that, I've never seen a magic potion called out
   on the installation drawings for any crimped terminal going into
   a production airplane. There is a VERY strong reluctance to
   use a design where "protective" processes are necessary or
   useful. We work hard to design out the need for any such
   techniques on the assembly line. Had a conversation just
   yesterday about a bofa-fide need to seal exposed terminals
   on a vendor supplied product that gets routinely rained on
   every time the airplane descends from altitude.

   We moved the sealing process from our assembly line to
   the manufacturer's facility where it can be inspected and
   controlled. There was no way we were going to ask a line
   mechanic to do this with repeatable results.

   Bottom line is that there may be a valid, engineered
   requirement for sprays, goops and goos in the assembly
   of your airplane . . . if you're concerned about a particular
   situation, let's pick it apart and discover the physics
   behind the need.

   Bob . . .






________________________________  Message 7  _____________________________________


Time: 09:37:46 AM PST US
From: "Jim Jewell" <jjewell@telus.net>
Subject: Re: AeroElectric-List: Re: Alternator speeds and belt tensions.

--> AeroElectric-List message posted by: "Jim Jewell" <jjewell@telus.net>


----- Original Message ----- 
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: AeroElectric-List: Re: Alternator speeds and belt tensions.

<snip>

> >The engine came with accessories and the "starter ring" had been modified
to
> >utilize a Gates Micro-V belt that drives the alternator.
> >He also made the 3.5" pulley It looks to me the fellow that made the
pulley
> >modifications did a great job and I will go with his idea until testing
and
> >actual use cause a change of course.
>
>     that was a LOT of trouble and expense for nearly
>     immeasurable benefit . . .

Right you are Bob,

It sure looks cool though! ... Lets just call it a dramatic non event (:-)!

Jim in Kelowna






________________________________  Message 8  _____________________________________


Time: 10:33:54 AM PST US
From: Sigma Eta Aero <sigmatero@yahoo.com>
Subject: Re: AeroElectric-List: relay diagram for Microair PTT

--> AeroElectric-List message posted by: Sigma Eta Aero <sigmatero@yahoo.com>

--0-1913595621-1065116012=:42806

www.microair.com.au/admin/uploads/ 760_install_&_user_manual_ver_M.pdf


It's hard to read for some reason in this PDF but in my manual (hardcopy with the
radio) it's on about page 20 and is the third "option" called "PTT relays for
single mic operation".

I asked a fellow here at work and he said just use two dpdt relays and wire the
appropriate terminals for NC and NO but I'm wanting specific suggestions for
relays that are small, light, and cheap (solid state maybe?).  

I'm surprised this hasn't been addressed before since it's a pain to get the co-pilot
to stop talking whenever you want to make a radio call.

Thanks!

Joa


++++++++++++++++++++++
"Robert L. Nuckolls, III" <bob.nuckolls@cox.net> wrote:
I'm not familiar with any schematics provided by
Microair that incorporate relays. Can you point me to
an internet resource where I can find the drawing
in question?


---------------------------------
--0-1913595621-1065116012=:42806

<DIV>
<DIV><FONT color=#008000>www.microair.com.au/admin/uploads/ 760_install_&amp;_user_manual_ver_M.pdf</FONT></DIV><FONT color=#008000></FONT></DIV>
<DIV><FONT color=#008000></FONT><FONT color=#008000></FONT>&nbsp;</DIV>
<DIV><FONT color=#008000>It's hard to read for some reason in this PDF but in my
manual (hardcopy with the radio) it's on about page 20 and is the third "option"
called "PTT relays for single mic&nbsp;operation".</FONT></DIV>
<DIV><FONT color=#008000></FONT>&nbsp;</DIV>
<DIV><FONT color=#008000>I asked a fellow here at work and he said just use two
dpdt relays and wire the appropriate terminals for NC and NO but I'm wanting
specific suggestions for&nbsp;relays&nbsp;that are small, light, and cheap (solid
state maybe?).&nbsp; </FONT></DIV>
<DIV><FONT color=#008000></FONT>&nbsp;</DIV>
<DIV><FONT color=#008000>I'm surprised this hasn't been addressed before since
it's a pain&nbsp;to get the co-pilot to stop talking whenever you want to make
a radio call.</FONT></DIV>
<DIV><FONT color=#008000></FONT>&nbsp;</DIV>
<DIV><FONT color=#008000>Thanks!</FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV>Joa</DIV>
<DIV>&nbsp;</DIV>
<DIV><BR>++++++++++++++++++++++<BR><B><I>"Robert L. Nuckolls, III" &lt;bob.nuckolls@cox.net&gt;</I></B>
wrote:<BR>I'm not familiar with any schematics provided
by<BR>Microair that incorporate relays. Can you point me to<BR>an internet
resource where I can find the drawing<BR>in question?<BR><BR><BR><BR><BR></DIV><p><hr
SIZE=1>
--0-1913595621-1065116012=:42806--






________________________________  Message 9  _____________________________________


Time: 10:57:14 AM PST US
From: "Phil Birkelbach" <phil@petrasoft.net>
Subject: AeroElectric-List: GPS-35 / Transponder / Autopilot

--> AeroElectric-List message posted by: "Phil Birkelbach" <phil@petrasoft.net>

I am going to have the Garmin GPS-35 feeding the heading info to my TruTrak
autopilot and I was wondering if I could also hook this signal up to my
Garmin GTX-327 transponder for the automatic ALT/STBY switch?  I would
assume that if I paralleled the two that it may work but I thought that I
would ask.

Godspeed,

Phil Birkelbach - Houston Texas
RV-7 N727WB (Reserved) - Canopy
http://www.myrv7.com






________________________________  Message 10  ____________________________________


Time: 12:57:34 PM PST US
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: relay diagram for Microair PTT

--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>

At 10:33 AM 10/2/2003 -0700, you wrote:
>--> AeroElectric-List message posted by: Sigma Eta Aero <sigmatero@yahoo.com>
>
>--0-1913595621-1065116012=:42806
>
>www.microair.com.au/admin/uploads/ 760_install_&_user_manual_ver_M.pdf
>
>
>It's hard to read for some reason in this PDF but in my manual (hardcopy 
>with the radio) it's on about page 20 and is the third "option" called 
>"PTT relays for single mic operation".
>
>I asked a fellow here at work and he said just use two dpdt relays and 
>wire the appropriate terminals for NC and NO but I'm wanting specific 
>suggestions for relays that are small, light, and cheap (solid state maybe?).
>
>I'm surprised this hasn't been addressed before since it's a pain to get 
>the co-pilot to stop talking whenever you want to make a radio call.
>
>Thanks!

   Downloaded the manual . . . UGHhhhh! I offered to do
   real wiring diagrams that depicted how to connect
   wires together and now I see that the latest manual
   is not only worse for diagrams, (nobody should attempt
   to hook up the system in the manner depicted) the .pdf file
   was generated with some odd-ball font that probably only
   prints in part of the world.

   Okay, you want opposite mic disable when a PTT button
   is pushed. Do you want the copilot to have radio access
   too or just intercom? Let's figure out what's needed
   and do a real wiring diagram.

   Bob . . .






________________________________  Message 11  ____________________________________


Time: 01:52:23 PM PST US
From: Sigma Eta Aero <sigmatero@yahoo.com>
Subject: Re: AeroElectric-List: relay diagram for Microair PTT

--> AeroElectric-List message posted by: Sigma Eta Aero <sigmatero@yahoo.com>

--0-1573740537-1065127919=:49265


You mean an intercom that requires a button to be pushed to talk to the co-pilot?
No, I'm fine with the always hot intercom, it's just the always hot PTT (transmit
on the radio) that I don't like.  


I would like both the pilot and the co-pilot to have PTT buttons and when one pushes
theirs it cuts the other person off from talking.


If you can't read the diagram I can describe what they are doing (though you obviously
know already Im sure).  Both relays have one NC terminal going to each
mic ring terminal and another terminal in parallel with each other going between
the PTT pin (7) and ground.  Basically it works so when one PTT is pushed
that relay closes the radio PTT circuit and opens the other persons microphone
connection so that they cant talk.


The Microair circuit looks fine and is pretty elementary(well, it is to me *after*
the EE from work explained it!).   Im just wanting your expertise in finding
a couple nice tiny (but inexpensive) relays (preferably something I can solder
in line and just cover with heat shrink) that will work with the currents
we have here.


Would be great though if you could add this feature to your manual since as you
noticed the Microair manual is pretty lacking!  Im sure others that arent using
a separate intercom would benefit.


Thanks Bob!


Joa

"Robert L. Nuckolls, III" <bob.nuckolls@cox.net> wrote:
Okay, you want opposite mic disable when a PTT button
is pushed. Do you want the copilot to have radio access
too or just intercom? Let's figure out what's needed
and do a real wiring diagram.


---------------------------------
--0-1573740537-1065127919=:49265

<DIV>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY:
Arial">You mean an intercom that requires a button to be pushed to
talk to the co-pilot?&nbsp; No, I'm fine with the always hot intercom, it's just
the always hot PTT (transmit on the radio) that I don't like.&nbsp; <?xml:namespace
prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY:
Arial"><o:p>&nbsp;</o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY:
Arial">I would like both the pilot and the co-pilot to have PTT buttons
and when one pushes theirs it cuts the other person off from talking.<o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY:
Arial">&nbsp;<o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY:
Arial">If you can't read the diagram I can describe what they are doing
(though you obviously know already Im sure).&nbsp; Both relays have one NC
terminal going to each mic ring terminal and another terminal in parallel with
each other going between the PTT pin (7) and ground.<SPAN style="mso-spacerun:
yes">&nbsp; </SPAN>Basically it works so when one PTT is pushed that relay
closes the radio PTT circuit and opens the other persons microphone connection
so that they cant talk.<o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY:
Arial"><o:p>&nbsp;</o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY:
Arial">The Microair circuit looks fine and is pretty elementary(well,
it is to me *after* the EE from work explained it!). <SPAN style="mso-spacerun:
yes">&nbsp;&nbsp;</SPAN>Im just wanting your expertise in finding a couple
nice tiny (but inexpensive) relays (preferably something I can solder in line
and just cover with heat shrink) that will work with the currents we have here.<o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY:
Arial"><o:p>&nbsp;</o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY:
Arial">Would be great though if you could add this feature to your
manual since as you noticed the Microair manual is pretty lacking!<SPAN style="mso-spacerun:
yes">&nbsp; </SPAN>Im sure others that arent using a separate intercom
would benefit.<o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY:
Arial"><o:p>&nbsp;</o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY:
Arial">Thanks Bob!<o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY:
Arial"><o:p>&nbsp;</o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY:
Arial">Joa<o:p></o:p></SPAN></P><BR><B><I>"Robert L. Nuckolls, III"
&lt;bob.nuckolls@cox.net&gt;</I></B> wrote:</DIV>
<BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT:
#1010ff 2px solid">Okay, you want opposite mic disable when a PTT button<BR>is
pushed. Do you want the copilot to have radio access<BR>too or just intercom?
Let's figure out what's needed<BR>and do a real wiring diagram.<BR><BR></BLOCKQUOTE><p><hr
SIZE=1>
--0-1573740537-1065127919=:49265--






________________________________  Message 12  ____________________________________


Time: 02:15:18 PM PST US
From: Charlie Kuss <chaskuss@bellsouth.net>
Subject: Re: AeroElectric-List: Use of individual wires from a Mil-Spec
  C-27500 cable

--> AeroElectric-List message posted by: Charlie Kuss <chaskuss@bellsouth.net>

At 10:18 AM 10/2/2003 -0500, you wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
>
>At 11:11 PM 10/1/2003 -0400, you wrote:
>>--> AeroElectric-List message posted by: Charlie Kuss <chaskuss@bellsouth.net>
>>
>>Bob & Listers,
>>  I was given a large quantity of Mil Spec Aviation wiring from a friend. 
>> Some of this wire was 22 & 20 gauge C-27500 shielded 2 & 3 wire cable. 
>> Some of this cable had been stripped of it's outer sheath and shielding. 
>> This cable has color coded wires inside (red, blue & yellow). Are these 
>> individual wires OK to use on my RV-8A project? It appears that the 
>> insulation is slightly thinner on these wires as compared to individual 
>> Mil 22759/16 wires. I'd like to use this wire, but I want to make sure 
>> that I am not "cutting corners" in doing so. Opinions please.
>>Charlie Kuss
>>RV-8A  going cross eyed looking at wiring schematics
>>SE Florida
>
>   Mil-C-27500 is an ASSEMBLY specification for bringing a variety
>   of materials (wires, shielding and outer jackets) together into
>   bundles of wire that may be shielded. See:
>
>   http://www.awcwire.com/pdf/CT-G4-M27500.pdf
>
>   Given the relatively modern incarnation of this specification
>   it is unlikely that anything you find assembled under it
>   will be unsuited for use in your airplane. I'd say, "drive
>   on and let not your heart be troubled."
>
>   Bob . . .

Bob,
 Thanks for your opinion. My mind is now relieved!   :-)    I had already visited
the web page listed above. I have even printed it out. I like the table which
explains what the numbers after the  / in the Mil-Spec number mean. (They relate
to the type of insulation on the wire)  I've found several other useful
pages on Allied's site.
Charlie Kuss






________________________________  Message 13  ____________________________________


Time: 02:15:18 PM PST US
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: AeroElectric-List: Re: Low voltage warning circuit

--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>


>
>
>On the schematic and BOM (9021-620 dated 9/14/2) R116 is 68 but in the 
>pictures included in
>
><http://www.aeroelectric.com/articles/lvwarn/9021-620.pdf>http://www.aeroelectric.com/articles/lvwarn/9021-620.pdf 
>this resistor is 62.  Now if each is off the 5% tolerance in the right 
>direction this won t matter mathematically but I can t judge how this 
>otherwise affects the circuit, nor can I assume that there will be a 
>statistical fluke making my point moot, so I need to ask what is the 
>correct value?

    <snip>

   I bashed this out in a hurry but I think the schematic and
   BOM have been brought into agreement with present
   manufacturing configuration.

   See http://www.aeroelectric.com/articles/lvwarn/9021-620.pdf

   If you've downloaded this recently, your browser may have
   the old version in cache . . . hit the reload button after
   download to make sure you get the latest. The schematic
   and BOM pages will have Rev A 10/2/3 in the title block
   on the latest document.

   Bob . . .






________________________________  Message 14  ____________________________________


Time: 02:39:08 PM PST US
From: "RSwanson" <rswan19@comcast.net>
Subject: Re: AeroElectric-List: relay diagram for Microair PTT

--> AeroElectric-List message posted by: "RSwanson" <rswan19@comcast.net>

 > I asked a fellow here at work and he said just use two dpdt relays and
wire the appropriate terminals for NC and NO but I'm wanting specific
suggestions for relays that are small, light, and cheap (solid state
maybe?).

Try http://www.jameco.com/ , they have a nice assortment of solid and coil
relays at very reasonable prices.
R






________________________________  Message 15  ____________________________________


Time: 02:57:54 PM PST US
From: "Eric M. Jones" <emjones@charter.net>
Subject: AeroElectric-List: Re: Dielectric grease recommendations 

--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>

Many people think a dielectric grease might contaminate the surface of a
conductor. Of course this is not true, the grease merely fills in the air
gaps. Although a "proper" crimp may be gas tight, only the conductor under
the crimp is so blessed.

Under a microscope the cable will be seen to possess many small channels in
the pack. In theory, the channels can wick moisture and contaminants
(historically battery acid) into the crimp. Why is this a concern? If all
the metal in the joint were the same, we might still want to exclude water
because it can freeze and force the joint open. However, a more critical
need is to seal the airspaces because of the likelihood that electrolytic
corrosion will occur. The metal crimp itself may be aluminum or brass or
copper, the plating may be nickel or more likely tin, and the wire may be
copper, and ever nickel tin or zinc plated. So electrolytic corrosion can
occur.

Indoors this is rarely an issue, but aircraft see a lot of water in their
lives; it's a good idea to keep it out of the crimp.

Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones@charter.net

When the Okies moved  to California they raised the average IQ of both
states.
   ---Will Rogers






________________________________  Message 16  ____________________________________


Time: 05:54:57 PM PST US
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: relay diagram for Microair PTT

--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>

At 01:51 PM 10/2/2003 -0700, you wrote:
>--> AeroElectric-List message posted by: Sigma Eta Aero <sigmatero@yahoo.com>
>
>--0-1573740537-1065127919=:49265
>
>
>You mean an intercom that requires a button to be pushed to talk to the 
>co-pilot?  No, I'm fine with the always hot intercom, it's just the always 
>hot PTT (transmit on the radio) that I don't like.
>
>
>I would like both the pilot and the co-pilot to have PTT buttons and when 
>one pushes theirs it cuts the other person off from talking.
>
>
>If you can't read the diagram I can describe what they are doing (though 
>you obviously know already Im sure).  Both relays have one NC terminal 
>going to each mic ring terminal and another terminal in parallel with each 
>other going between the PTT pin (7) and ground.  Basically it works so 
>when one PTT is pushed that relay closes the radio PTT circuit and opens 
>the other persons microphone connection so that they cant talk.

    Wasn't concerned about reading Microair's diagram, just
    wanted to know how you wanted the system to work. The important
    part of working is do you want pilot priority (pushing pilot
    PTT overrides copilot even if already pushed) or mutual priority
    (first come first served with no override from either position).


>The Microair circuit looks fine and is pretty elementary(well, it is to me 
>*after* the EE from work explained it!).   Im just wanting your expertise 
>in finding a couple nice tiny (but inexpensive) relays (preferably 
>something I can solder in line and just cover with heat shrink) that will 
>work with the currents we have here.

    Tiny relays and soldering in-line are mutually incompatible
    features. Tiny relays mount to etched circuit boards and
    very non-robust terminals. Years ago, the relay of choice
    for what you're wanting to do was Potter-Brumfield 4PDT
    KHA series relays. They're cheap from Digikey (cat #PB142),
    and can either be soldered to directly with wires and heat-
    shrink or you can install them in a socket (Cat #PB144) and
    hold relay in place with spring wire bail (Cat #PB146).


>Would be great though if you could add this feature to your manual since 
>as you noticed the Microair manual is pretty lacking!  Im sure others that 
>arent using a separate intercom would benefit.

    I can do that, but it's two drawings to offer the
    variants cited above.


    Bob . . .

    PS. get into your email client option and shut off the HTML feature.
    Your message to the list was transmitted in both text and
    html . . .






________________________________  Message 17  ____________________________________


Time: 06:22:27 PM PST US
From: Sigma Eta Aero <sigmatero@yahoo.com>
Subject: Re: AeroElectric-List: relay diagram for Microair PTT

--> AeroElectric-List message posted by: Sigma Eta Aero <sigmatero@yahoo.com>

--0-381469590-1065144131=:62240


Whichever is easier.  Probably first come first served since I will be flying from
the back seat a bit (or I wouldn't even put a PTT there).

Also, I assume diodes will have to go across the switching contacts to prevent
spikes?

Don't know what to do about the HTML messages- I'm using Yahoo Mail and went into
preferences but couldn't find any way to switch it off.  

Thanks!

Joa


**********************************************************
Wasn't concerned about reading Microair's diagram, just
wanted to know how you wanted the system to work. The important
part of working is do you want pilot priority (pushing pilot
PTT overrides copilot even if already pushed) or mutual priority
(first come first served with no override from either position).


---------------------------------
--0-381469590-1065144131=:62240

<DIV>
<BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT:
#1010ff 2px solid">
<P>Whichever is easier.&nbsp; Probably first come first served since I will be
flying from the back seat a bit (or I wouldn't even put a PTT there).</P>
<P>Also, I assume diodes will have to go across the switching contacts to prevent
spikes?</P>
<P>Don't know what to do about the HTML messages- I'm using Yahoo Mail and went
into preferences but couldn't find any way to switch it off.&nbsp; </P>
<P>Thanks!</P>
<P>Joa</P>
<P>&nbsp;</P>
<P>&nbsp;</P>
<P>**********************************************************<BR>Wasn't concerned
about reading Microair's diagram, just<BR>wanted to know how you wanted the
system to work. The important<BR>part of working is do you want pilot priority
(pushing pilot<BR>PTT overrides copilot even if already pushed) or mutual priority<BR>(first
come first served with no override from either position).<BR><BR></P></BLOCKQUOTE></DIV><p><hr
SIZE=1>
--0-381469590-1065144131=:62240--






________________________________  Message 18  ____________________________________


Time: 07:13:56 PM PST US
From: "Richard Sipp" <rsipp@earthlink.net>
Subject: Re: AeroElectric-List: Re: Alternator speeds and belt tensions.

--> AeroElectric-List message posted by: "Richard Sipp" <rsipp@earthlink.net>


Sorry that I can't quote a source, but recently I read that a practical way
to measure drive belt tension on an alternator is to measure the torque
required to turn the alternator pulley until it slips in the pulley with the
belt adjusted where you think it should be.    Unfortunately I also don't
recall what the suggested torque reading was...maybe 10 ft. lbs.  Anyway, it
should be easy to set by any other method and then measure the "slip"
torque.

Dick Sipp
RV10 N110DV
RV4 N250DS






________________________________  Message 19  ____________________________________


Time: 08:50:55 PM PST US
From: "Steven DiNieri" <capsteve@adelphia.net>
Subject: RE: AeroElectric-List: Re: Low voltage warning circuit

--> AeroElectric-List message posted by: "Steven DiNieri" <capsteve@adelphia.net>


Bob, how could I make the low volt warning threshold adjustable or lower
than 13v? 
        I need a device to monitor rear batteries under load in a "rec
vehicle" and trigger a remote start at a voltage just above the typical
alarm in a large power inverter. 

Steve DiNieri
Rv-6a n221rv


    <snip>

   I bashed this out in a hurry but I think the schematic and
   BOM have been brought into agreement with present
   manufacturing configuration.

   See http://www.aeroelectric.com/articles/lvwarn/9021-620.pdf

   If you've downloaded this recently, your browser may have
   the old version in cache . . . hit the reload button after
   download to make sure you get the latest. The schematic
   and BOM pages will have Rev A 10/2/3 in the title block
   on the latest document.

   Bob . . .