Jeff Pryor's P-51 Avionics
It is owned by Jeff Pryor and is kept in Santa
Barbara CA. All sun damaged King radios are coming out, New panel being cut.
KCS 55A being replaced with PN 101 because the Collins unit can handle the
aerobatics. GNS 480 is going in and will code a
remote GTX 32 mounted in the hell-hole where the current Narco DME, KN 75, and
KG-102 gyro now live. We're not sure about the #2 nav comm or the audio system
yet, those issues are still to be determined. Jeff wants to have a balanced
instrument panel and we're trying to come up with the best looks along with the
best functionality. The 480 will be mounted in the lower panel under the main
instrument panel where the armament control panel use to be. The # 2 Nav/Comm
was to be an SL 30 mounted under a PMA 7000B in the lower left portion of the
instrument panel, however, after discussing the overall look and the mismatch of
round mixed with square in the instrument panel. We are looking into the PMA
4000 round along with the Becker Nav and Comm units to keep it all round in the
panel. Jeff wants good looks and balance along with quality.
When Jeff first came to Santa Maria
for me to look his plane over he had complete audio failure in flight.
Luckily he was on his way to an avionics shop. Troubleshooting revealed that
his KMA 24 audio panel speaker output had been wired through an impedance
matching transformer for 600 ohms and was driving his headphones. This is
understandable because usually pilots who fly these war birds wear earplugs
inside their headsets to keep out the engine roar. So its necessary to have an
amplifier loud enough to penetrate all of this. The problem in this case is
that who ever wired up the audio in this way did achieve the volume necessary
but forgot to put in safeguards to avoid overdriving the headphone speakers in
the event full volume was inadvertently applied which was the case. We not only
blew out his helmet speakers but also my headset in the process of
troubleshooting. Also this configuration does not allow communications between
the pilot and the rear seat passenger over an ICS. Our plan is to go the other
way and boost the headphone output of a PMA 4000 instead of reducing the speaker
out. We'll figure it out.
Here are some of the pictures Steve took
prior to the aircraft being disassemble. Stay tuned, this should be
The above was written by Steve Walker, owner of
Avionics West in Santa Maria CA.