The AM Forum

Each April 1 it’s become a tradition with me to search the Internet for the best April Fools media releases. NPR’s story of the exploding maple trees in the VT woods is by far the best I found. This year I decided to introduce this topic early, in case others wanted to share.

Before he passed away  my elmer, W2MJD, gave me a very old April Fools promo item that Muter gave it’s distributors. It dates back to the 1920’s. In early receivers, we changed the value to the grid leak resistor to vary the gain. The resistor was a cartridge type resistor, similar to a fuse.  Muter created a “Grid Leak Drip Pan” for its distributors. I’ve mentioned it to a few people who quickly dismissed it as folklore. It’s real!

One more photo

Would probably also be useful to catch the relative bearing grease leakage from a gyro.

Pretty neat.

But everybody knows a true grid leak base pan has higher rims as well as a discharge stopcock, discharge tubing, filter and variable speed re-circ pump driven by audio output.

The hysteresis was always a problem, so astute builders included a wavelength timed integrator in the audio stream to catch proper phase to simulate correct signal arrival time.
This was the technology that gave some smart op. the idea for AVC in later improved TRF"s.

Lest you think I'm making this up because your idea of an integrator involves fancy solid state op amps and stuff, an integrator in those days was simply a couple of variable RC circuits in series. Integrators, differentiators and phase lag or lead circuits are essentially the same.

Honestly I don't know what JN's expect to be spoon fed these days.  ;D

Somewhat off the subject on a tangent, but what the heck: I drove an MGA for years. MGAs and MGBs were infamous for their rear main engine seal oil leaks. The largest purveyor of MG parts, Moss Motors, actually sold a small pan that was bolted between the transmission and engine to catch the leaking oil.

Interesting.  But I thought that the filter and variable speed recirculating pump were 'recent' additions due to EPA and OSHA since some of the liquified errant electrons could possibly be 'hazardous' and therefore needed to be filtered before being used further.  Or, like a lot of labels say "known to be hazardous to the State of California".

Hmm, you might be right, the fog of memory, you know, but I think it was USArmy Corps of Engrs, a/c stream pollution or maybe they just piled on with more regs. later.  ;D

Say I had a 67 MGB -GT BRG and yes it was the big end bearing seal leaking into the xmission housing. The Queen paid a lot of dealers for warrenty change outs on that one. Do you remember the clutch pedal spring breaking and springing out to hit you in the crotch at exactly 35,000 miles or the rr fender fuel pump breaking at about the same time and the speedo cable doing same?  ...and on and on...

But oh, did I love that car. --Kept a bed roll on the rear shelf not thinking it was exposed via rear glass.

My first MG was a '70 B roadster. LOVED that car, was well worth the $500 I paid in late '79. Drove it all over New England, from VT to Maine and NH where my GF lived, without ever having a spare tire. Not sure if you'd call it trusting or foolish? Had three of them, though. Sold the second before it was finished. Lost the throw out bearing in the third one while in rush hour traffic but limped it home. A friend helped with the clutch job but a week or so later the throttle cable broke. Quick trip to a music shop for some guitar strings got me going again but it broke again. Burned off, actually. Turns out we forgot the bonding strap between the engine and frame. Ooops! Final cable was a bicycle handbrake cable from dept store. Couldn't tell the different from original aside from the white jacket. Ended up wrecking it later then rebuilding and selling it the following year.

Biggest problem I ever had with any Brit car was some knot head previous owner dumping non-Girling rated brake fluid into the master cylinder. Electrical problems were a given with the ancient style bullet connectors, but simple (if not tedious) to remedy.

Love the Grid Leak drip pan sample. Would love to find one for the collection here. Those old timers were pretty sharp in their days, albeit with a somewhat different sense of humor compared to today.