Jerry 5TJ

Well, we all agree qualitatively -- pathetically low production figures.

Production was 14 last year.....

Darn.

The Plane & Pilot e-article says the company will not be making parts for sale. https://www.planeandpilotmag.com/article/mooney-ceasing-production/#.XctYH2ROnDt

Except for the ones made of wood.

OK —Tesla 3 production in Q3 of 2019 was just under 80,000 cars. Over 25,000 per month. Working 24/7 about one complete car every 100 seconds.

A good approximation but that’s not quite the specified test of voltage vs time at a constant current = 1C rate. I use an electronic load ($130 on eBay) in series with a water-cooled 1 ohm resistor (a bank of 50W resistors in parallel in a plastic tub of water) to test my 28V 12 AH Concorde batteries. A logging DVM ($40 off eBay) takes a voltage reading every 10 seconds. The electronic load holds the test current steady at the required 12.0 amps. A graph of V vs time goes in the logs. All that said, in my Mooneys I just got a new battery when the old one would no longer crank the engine well on a cool morning. This is the result of two batteries tested for 60 minutes. They show >100% of rated 1C capacity.

According to the Wikipedia Oracle, more C models were built than any other. https://en.m.wikipedia.org/wiki/Mooney_M20 Far more pre-J aircraft were built than all the J and later models combined. The “center of mass” for Mooney production is about 1972.

The “Kinds of Equipment” list for the Ovation says 2 batteries for all operations.

Great facility! Think I’ll write a grant proposal to evaluate the relative efficacy of WD-40, ice-off, Rain-X and PUDS (pilot urine delivery systems) on ice formation on low-sweepback airfoils. Alan, please cut me a 3-4 foot chunk of wing section out of your next vivisection subject. Spar corrosion optional.

I know this thread is just plain fun (clever, get it?) but to revert to my EE life for a moment—do the arithmetic to estimate how many watts of electric power you’d need to thaw ice off a hundred square feet of aluminum in a 200 mph airflow at -5C. Maybe buy a surplus APU from an Airbus 320. 90,000 watts electric output. Might do it. I’ll check eBay. When you don’t need it to deice the wings the APU can drive an electric motor attached to my M20C O-360 crankshaft for some extra thrust. Let’s see, 90,000 watts is around 120hp, a nice boost. With an extra 120 hp my old C would cruise about as fast as the average Mooneyspace C. Not as fast as an E, of course.

Well, FIKI = flight INTO known icing. Does not say that you will fly OUT....

The part I don't get is how pulling the power on #1 radio affects the #2 radio PTT operation. Perhaps an effect from the "fail-safe" features of the PMA450A. Ignore that symptom for now... Your test of wiggling the wire bundle sounds significant. The PTT switches in the yoke are routed to the audio panel. The audio panel then routes the PTT signal (grounding the PTT pin enables transmission) to the appropriate radio. Here's a bit of the PMA450A Schematic: You can see that the PTT runs from the audio panel to each radio. That's how the correct transmitter is keyed based on the XMT selector switch of the PMA450A. If you remove the PMA450A from its rack and can reach the pins of J1 down inside the rack, check the resistance of pin 30. It should show a high resistance relative to aircraft ground. If you wiggle the wire bundle and that resistance drops to a lower value (a few dozen ohms or less) then you may have found the culprit -- an intermittent short to ground on that wire.

The KY197 is a good but 40+ year old radio. They are widely available on the used market for a few hundred dollars so paying to repair yours is most likely uneconomical. A quick bench test by an Avionics tech will confirm if it is dead.

Yes, find the drafts and seal them. Yes, check the tubing that’s supposed to deliver heater air to the rear as they deteriorate in a decade or three. But it’s always going to be cold back there on a dark winter flight. How about adding some seat heat? Like This? Get rid of your 10 amp Incandescent landing light (go LED) and use the juice to warm your whatever. STC pending.