Transponder Ant. was Re: REFLECTOR:anntenas

[Jim Agnew]

Scott,

The connectors are very important and you should use high
grade hex crimp connectors with gold pins for maximum
signal.  You can cut the connector off one cable end and
connect the new cable with solder and tape wraps to make
sure it is smooth and then lubricate the cable and pull it
through then install the connector after cutting the cable
and cleaning it. 

If you have an AMP Pro-Crimper with the HEX crimp jaws you
can install the connectors in a few minutes.  The ground
plane plate should be larger in length and width than the
antenna is long assuming that the antenna is the standard
rod type and mount it with the antenna pointing DOWN.

Jim




--- Scott Derrick <scott@tnstaafl.net> wrote:
> I wonder which would be more difficult, pulling new coax
> through the 
> very full conduit or mounting a new antenna.
> 
> I'd prefer leaving it where it is.  I think I'll price
> out the 142 stuff.
> 
> I've also found two connectors in the transponders coax
> line, I have no 
> idea why. Each of these contributes a bit to the loss.
> 
> Scott
> 
> 
> Jim Agnew wrote:
> > Your antenna placement is fine, it is the loss in the
> coax.
> >  The standard coax is good for 8-9 feet, for distances
> up
> > to about 17 feet use RG-142 coax.  It is much lower in
> loss
> > but you might get sticker shock on cost.  It is a
> special
> > Mil Spec coax.
> > 
> > Jim
> > --- Scott Derrick <scott@tnstaafl.net> wrote:
> > 
> >>I'll second Wayne's "DO NOT" for the transponder. Mine
> is
> >>in the strake 
> >>in the outside wing bolt hole space.  I get periodic
> >>complaints from ATC 
> >>about intermittent transponder.  I think I'll purchase
> >>another antenna 
> >>and try mounting one closer to the transmitter.
> >>
> >>I don't want it out side though, don't have any
> external
> >>antennas now, 
> >>and don't want any.
> >>
> >>Where's a good spot in a standard RG?  I was thinking
> >>about mounting it 
> >>to the bottom of the rear seat?
> >>
> >>How big does the ground plane need to be?
> >>
> >>My GPS antenna is mounted to the inside of the nose
> >>access door, 4 feet 
> >>of cable and works great.
> >>
> >>Scott
> >>
> >>Wayne Lanza wrote:
> >>
> >>>
> >>>Regarding the antennas, our experience at the builders
> >>
> >>center points to 
> >>
> >>>the following:
> >>> > Transponder ANT = between the firewall and gear
> bulk
> >>
> >>head, on center 
> >>
> >>>line. DO NOT
> >>>put this ANT out in the strake, many transponders
> don't
> >>
> >>like to drive 
> >>
> >>>this much wire!
> >>> > GPS = on top of the landing light or on top of the
> >>
> >>canard, keep this 
> >>
> >>>wire under 8' long.
> >>> > Marker Beacon = Inside or outside of the keel, or
> on
> >>
> >>the floor near 
> >>
> >>>the keel. Locate
> >>>the foil such that you don't tear it up when
> >>
> >>upholstering or mounting 
> >>
> >>>the seats...
> >>> > Glide Slope = On the floor under the copilot front
> >>
> >>seat area.
> >>
> >>> > AM/FM = Not too critical, string a 23" piece of the
> >>
> >>ANT wire (center 
> >>
> >>>conductor only)
> >>>across the under side of the structure in front of the
> >>
> >>canopy. Make sure 
> >>
> >>>that the pitch
> >>>trim spring doesn't interfere.
> >>> > ELT = Mount the ELT to the floor between the gear
> >>
> >>bulk head and the 
> >>
> >>>keel bulk head
> >>>on the copilot side. Run two 23" foils on a diagonal
> >>
> >>centered at the 
> >>
> >>>fuselage joint, the
> >>>angle of the foils is such that they are fairly
> >>
> >>straight (they might 
> >>
> >>>wrap onto the ceiling).
> >>>This is not super critical, but this antenna should be
> >>
> >>vertically 
> >>
> >>>mounted not horizontal!
> >>>Use the torroids and connect the coax braid to the
> >>
> >>lower foil. Secure 
> >>
> >>>foils, torroids and
> >>>the end of the lead in coax with 1 ply of bid. This
> >>
> >>needs to be 
> >>
> >>>shock/impact secured.
> >>> > ADF = I've heard of them :-)
> >>>
> >>>In general, use the correct type of coax (not TV wire
> >>
> >>or solid center 
> >>
> >>>conductor), use the
> >>>proper BNC terminals and appropriate tools. Keep the
> >>
> >>coax runs short and 
> >>
> >>>secure.
> >>>
> >>>Fly Safe,
> >>>Wayne Lanza
> >>>Composite Design, Inc.
> >>>(electrical weenie at the Velocity Builder's Center)
> >>>
> >>
> >
>
____________________________________________________________________
> > 
> >>>On Friday, April 11, 2003, at 06:37 AM, Lynn Gallup
> >>
> >>wrote:
> >>
> >>>    Noel,
> >>>    As near as possible, I followed the suggestions in
> >>
> >>the Velocity
> >>
> >>>    manual. After 185 hours flying my airplane in a
> >>
> >>wide variety of
> >>
> >>>    circumstances I can pronounce perfect operation of
> >>
> >>my nav & com
> >>
> >>>    radios, localizer & glideslope, marker beacon
> >>
> >>receiver and
> >>
> >>>    transponder. Even the ADF works acceptably
> although
> >>
> >>its range is a
> >>
> >>>    little short. The GPS would benefit from shielding
> >>
> >>or a slight
> >>
> >>>    relocation as it will blank out if one of the nav
> >>
> >>receivers is tuned
> >>
> >>>    to a particular VOR frequency. (Leakage of nav's
> IF
> >>
> >>frequency signal
> >>
> >>>    out of the localizer antenna overcomes the
> >>
> >>satellite signals.)
> >>
> >>>    Mine is a hatch door, long wing, RG. The antenna
> >>
> >>locations are:
> >>
> >>>    Com antennas - In the tip sails.
> >>>    Nav antenna - One shared antenna on top of
> fuselage
> >>
> >>about four
> >>
> >>>    inches forward of engine bulkhead.
> >>>    Marker beacon antenna - Along right side about two
> >>
> >>inches below
> >>
> >>>    windows.
> >>>    Transponder antenna - Bottom of fuselage below
> >>
> >>right rear seat.
> >>
> >>>    ADF antennna - Bottom of fuselage below left rear
> >>
> >>seat.
> >>
> >>>    Localizer antenna - On canard top surface,
> >>
> >>center-line of fuselage.
> >>
> >>>    GPS antenna - Front of canard top, centered.
> >>
> >>Forward of localizer
> >>
> >>>    antenna. It should be remounted under the top of
> >>
> >>the fuselage above
> >>
> >>>    the localizer antenna.
> >>>
> >>>    Regards,
> >>>    Lynn
> >>>    =====================
> >>>    At 11:46 PM 4/10/2003 Thursday, you wrote:
> >>>
> >>>     
> >>>    Now that it's finally starting to warm up, I'm
> >>
> >>doing the planning
> >>
> >>>    for my summer project... The wings / canard.
> >>>    I realize that antenna placement is variable,
> >>
> >>But...
> >>
> >>>    What do I really need? Do I need a Com and Nav in
> >>
> >>each wing?
> >>
> >>>    Where's the best place for a glideslope antenna.
> >>
> >>The keel was
> >>
> >>>    already down when I got the kit.
> >>>    I assume the transponder would be best on the
> >>
> >>floor, and the gps on
> >>
> >>>    the ceiling.
> >>>    What about something for the am/fm?
> >>>    I've seen Don's elt antenna on the main wingspar
> >>
> >>shearweb, and it
> >>
> >>>    looked pretty survivable.
> >>>     
> >>>    What's popular / what's practical
> >>>     
> >>>    Noel 3suv103
> >>>
> >>>
> >>
> >>
> >>_______________________________________________
> >>To change your email address, visit
> >>http://www.tvbf.org/mailman/listinfo/reflector
> >>
> >>Visit the gallery!  tvbf:jamaicangoose
> > 
> > 
> > 
> > =====
> > James F. Agnew
> > Jim_Agnew_2@Yahoo.Com
> > Tampa, FL
> > Velocity 173 Elite Aircraft Completed
> > _______________________________________________
> > To change your email address, visit
> http://www.tvbf.org/mailman/listinfo/reflector
> > 
> > Visit the gallery!  tvbf:jamaicangoose
> > 
> 
> 
> _______________________________________________
> To change your email address, visit
> http://www.tvbf.org/mailman/listinfo/reflector
> 
> Visit the gallery!  tvbf:jamaicangoose


=====
James F. Agnew
Jim_Agnew_2@Yahoo.Com
Tampa, FL
Velocity 173 Elite Aircraft Completed