Jeff Pryor's  P-51 Avionics Installation

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.  P-51 InstallationGNS 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 fun!

The above was written by Steve Walker, owner of Avionics West in Santa Maria CA.

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Up Dates of the P-51D Installation


Phase I

Phase II

Phase III

Phase IV Complete


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