I have a Hickok 533A to test the older stuff, and a Sencore 154A for newer stuff.  both have their advantages.  the Sencore manual actually has the steps needed to develop a test for newer type tubes, based on what you find in the spec sheet for that tube.

the special sauce is knowing what each knob, dial, and button does on your tester, and what socket pins go where. got that, use your noggin, write down the new tube recipe for the future.

I don't see 31 mix ferrite in the Amidon spec sheets... I do see 43 listed up to 15 MHz primary range, with discussion up to 40 MHz.

curves for these mixes don't drop off like a crystal filter, but wander about a bit on the slope to -60 dB.  if you have multiple stages, you can stagger-tune them for flat response with a little extra amplification in a strip amplifier.  if this is for oscillator service, you shouldn't squeeg and stop at 19.2, but might have a little reduced output.  nothing critical unless you are building for Uncle Sam and there are 10 stages of rejection in the purchasing process.

43 ought to do you proud.  but I grew up using iron powder toroids, and the #2 mix is high-Q from 2 to 30 MHz.  it should be flatter.

general rule about Tyco (fka Amp)... the connectors may be inexpensive, may not be,  but there is almost always a tool involved, and the usual price is $280.

if the future product used 5000 12AX7A tubes in parallel, would that satisfy everybody?

"light bulb savers" were disk rectifiers, you got DC at the bulb.  cut half the wave off, reduced light.

old HS buddy W0SHR made his own Heathkit power supply for the HW-101 with a 150-watt light bulb in an open-base socket on the chassis.  the bulb was in series.  turn on AC power, the bulb was in series, and after you blinked at the light a few seconds you flipped up the second switch to bypass the bulb.

the technique has been used since at least the 30s as a test bench staple to see if the radio under test had a high current short in the power supply.

you can come up with a dozen ways to automate and shrink the circuit... NE555, Amperite relay, surplus dial-it-in variable time relays... but it all works the same in the end.

ad servers are often tricked by slicksters into serving up java or flash ads that contain drive-by malware.  the individual websites taking ads are victims like we are.  it's the web ad services that are the usual culprits, causing blocks on even reputable websites.

it's policing by complaint, so email the webmaster and say you are getting blocks against them.  they have to get the ad server outfits to whack the bad ads.

hacks me off, makes me reach for the soldering gun, but I can't access the right terminal to stop it.

the National Electric Code for North America says you have to use pliers to mechanically twist the bare wires together before using wire nuts... said twist to go down the insulation at least two turns.

there are plenty of connections inside walls (hopefully inside junction boxes with a wrap or three of PVC electrical tape for moisture protection, although you can probably knock out the walls in any house and find "blind connections" with no box, sometimes with no wire nuts!) that have not been twisted.  you can usually find them by lights that blink randomly, or dim when the furnace goes on.  sometimes they are found when the fire marshal is inspecting the scene.

Euro barrier blocks would not cut it here for line power.  there are scurvy spring-loaded backstab (spring leaf friction connector) blocks that somehow got UL certified, and I believe them to be no more reliable than backstab wiring devices, which arc and gouge the wire and usually wires fall out when you replace them with reliable screw fastened devices.  I like the Euros for LV work, but if you're a believer in that last quarter turn of the screwdriver, you can twist the terminals off the mounting strips in between.  I still like good old Cinch/Beau phenolic screw barrier blocks for thier ruggedness.

the gold standard wire nut is from Ideal, although 3M and Buchanan also have their adherents.

the standard is... if the wire slightly deforms and is held tight by the connection, without creating a fracture point, it's a good connection.  officially, if it isn't gas tight, it probably won't meet code.

Mouser, Digikey, Newark et al.  they just aren't local.  prior to the maker movement, which is a bunch of folks who got fed up and did something about no neighbor with tools and no local parts distributors, the "movement" was searching for something like "make 500 kilowatt Frikken (tm) laser for sharks" on the Internet, and then assembling parts.

unless you want to get a bunch of "free" phones to gut for microscopic parts you'll burn up in removal (2 year contract required,) the shack isn't a destination for us types.

they may not sell the clamshell, but I bet they will repair the headset, probably for a price.  although Heil is often claimed to be excellent at customer service.

The SB102 was a good rig for its day, and working, is quite good enough today.  AC5UP is just color-blind, he thinks he is seeing red when he looks at Heathkit.  it's hard for me to see how you can sink $200 or up in one unless it's been thrown under a pavement roller.  the big thing with those rigs is badly out of spec resistors, anything with power across it will have gone double value or worse.  driver circuit, osc circuits, all the 22K plate dropper resistors are suspect.  the A4 oscillator and audio stages, assume you need to shotgun the resistors.

that's some good Elmer you have.

EXTRA:  get a good guide onine or in paper and spend an hour a night.  I like the method behind Ham Test Online, but there are several good guides in paper that have brought a ton of hams to the full band plan.  work the Kenwood without fear, have fun.  parts are availiable where they are needed, when they are needed, the unobtanium stuff is probably not going to fail.  and if it does, consider you got it for a handshake and a smile.

RZP, used to call those "solenoid" wound coils back when they had varnished cotton insulation.

or a one-piece part, the old thermistor

http://www.digikey.com/catalog/en/partgroup/j201-j204-series/6374?mpart=B59201J0140B010&vendor=495&WT.z_ref_page_type=Part%20Search&WT.z_ref_page_sub_type=Part%20Detail%20Page&WT.z_ref_page_id=0

for one example.  because the part continues to generate a tub of heat after it has done its protection thing, switching it out with an RC or 555 timing circuit with a relay will be friendly to everything around it.

we have had digital transmissions for commercial broadcast for a long time now.

curiously enough, we have not had to dump all of our pre-90s design radios and stuff to get their signals.

even as a thought exercise, that should tell you that out of the tank and into the ether, signals is signals, and if it works in band X with known type equipment, it's the same thing.  if it's the same thing, you check the envelope and decode like you always did for that emission class.  doesn't matter if they have 20 100-watt triodes in parallel, a PWM FET output, or sparks in a bunsen burner flame, that's just how you encode it.

provide me a few pallets worth, and I'll teach ya

there are some internally fragile tubes that short if you look at them funny... the same audio tube used in the Heath SB/HW series is used in some Hammond organs.  looky here, they are prone to shorting suppressor to cathode. that burns up the limiting resistor if any, the rectifier, and the power transformer.

there are also a bunch of NOS tubes that have gassed up over the years, but sitting in the tester socket for a while can degas them.

two excellent reasons to have a tube tester.  and it's not necessary to have one box to test them all, and in the caddy bind them, if you get a newer tester and an older one at the right price.