Crystal Radio Parts, Variable Capacitors, Verniers, and Litz Wire

New Style 365 pf Variable Capacitor

I am pleased to announce a new style of the old 365 pf variable capacitor. This is like the old time capacitor that has been used for generations by dads and their kids making their first crystal radio.

But there have been some changes over the years, and this capacitor brings us in to this new century! These capacitors were spec'd by myself after many years of building radios using someone else's idea of the right capacitor. Now it is my turn!

I raised the capacitance from the usual 365 pf value (15-385 actually) up to a maximum of 410 pf. In the days since the 365 became standard, the MW band has expanded twice. First from 1500 to 1600 kHz in the early forties to 1700 kHz about 20 years ago. To easily cover the entire band without coil taps or external fixed capacitors, I have increased the range of this variable capacitor.

For some reason, the sellers of these capacitors have always specified that the two front mounting holes be in the upper corners. This makes drilling the holes accurately a hit or miss operation at best. (Did you ever try to move a hole?) Now the two front mounting holes have been moved so they are directly in line with the horizontal axis of the shaft.

Most builders mount the capacitor to the front panel. These capacitors can also be mounted using the two 6-32 tapped holes on the bottom of the capacitor. Caution: If you mount the capactors by the bottom, make sure to add some washers to space the capacitor from the chassis. Otherwise you will likely ruin the capacitor because the insulator becomes displaced.

The shaft length is usually 5/8 inch (15mm) long. I can't tell you how many times I have had troubles mounting knobs with so little shaft sticking out! If you try mounting to a panel thicker than 1/8 inch, it just doesn't work. The shaft on this capacitor is a full 7/8 inch (21 mm) long. This means there is no problem using an 1/8 inch panel with nearly any knob. A 3/16 inch panel is useable with some knobs.

I have explained all this to show you the difference between what I am offering and the "usual fare". My interest in not offer just a cheap price for something that will be sure to take the fun out of the hobby, but something that is designed right. This also explains why the price is somewhat higher. I had to pay extra for these changes. The margins on these caps are thin as they come already, so the price had to go up a bit. Below I show the listing for these capacitors.

Picture	Item #	Price	Description
	VERNIER	$11.50 Each	6:1 vernier drive. Newly made in the USA. 1/4 inch shaft. Comes with set screws and dial screws. Special: Six or more, $11 each.
	410pf	$13.00 Each	15-410 pf variable capacitor. Hardware provided for front panel mounting and solder lug grounding. 7/8 inch long shaft. Special: Six or more $12 each.
	LABELS	See Details	Laminated dial labels to calibrate your radio. Round dial plastic dial scales also available. Details available
	PT-4175W	$3.00 Each	Piezo element. Make headphones with these. More sensitive than many magnetic headphones. Mallory PT4175W same as # KBT-44SB-1A Special: $10/4, $20/10, $38/20
	MUFFS	$6.00 Each	Build your own PiezoPhones.

Picture	Item #	Price	Description
	KNOB27	$1.50 Each	1-1/16 inch diameter "stove top" style knob. 6 mm hole, with set screw. Use with imported controls. Special: $12/10
	KNOB6	$1.50 Each	Imported knobs. 6 mm hole, with set screw. Use with imported pots and switches. 5 colors available. Special: $12/10
	KNOB40	$3.50 Each	1-9/16 inch diameter VRL style knob. Holds a 6 mm shaft with two set screws. Special: $25/10, $40/20
	KNOB30	$2.00 Each	1-3/16 inch diameter VRK style knob. Holds a 6 mm shaft with two set screws. Special: $15/10, $25/20

Picture	Item #	Price	Description
	XTAL200K	$35.00 Each	Custom 200k input headphone autotransformer. Full details on my Überformer page.
	T725	$9.75 Each	The famous Bogen T725 audio matching transformer. Use as autotransformer with 40k ohm input impedance, with 150, 300, 600, 1200, 2500, 5000, and 10000 ohm outputs.
	12VDC	$2.00 Each	12 volt dc unregulated at 500 ma power supply with US 120 volt AC plug. 16 volts no load. Put several in series for B+ supply.

Picture	Item #	Price	Description
	6418	$8.00 Each	New old stock 6418 subminiature tube used in some of my radios. Special $30/4, $50/8
	1J24B	$5.00 Each	New old stock 1j24b Russian subminiature pentode tube 1.2 vdc filament. See this project.
	12Sh1L	7.00 Each	New old stock 12Sh1L Russian pentode tube 12.6v/75ma. heater. Loctal base. Aluminum jacket with pull knob on top.
	12Sh1L-SOC	12.00 Each	New old stock 12Sh1L Russian pentode tube 12.6v/75ma. heater. Loctal base. Aluminum jacket with pull knob on top. Ceramic loctal socket is included
	1J29B	5.00 Each	New old stock 1J29B (1Sh29b) Russian pentode tube. Filament: 2.4v/30ma or 1.2v/62ma. Ep=60v, Ip 5.3ma.
	1625 Socket	$5.00 Each	1625 ceramic tube socket.
	7AM1	$1.50 Each	Cinch 7AM-1, 7 pin top mounted miniature tube socket. Special: $13/10, $20/20
	7-P	$1.00 Each	7 pin phenolic miniature tube socket. Special: $4/5
	9-BIG	$4.00 Each	9 pin tube socket for larger tubes (24JE6, etc). Special: $10/3

Picture	Item #	Price	Description
	1N34A/10	$3.00/10	1N34A Germanium Diodes. Green cathode band. Special:$24/100
	FO-215	$1.50 Each	The FO-215 diode is a better replacement for the 1N34A diode in higher performance sets. Diodes have slight lead corrosion due to age. Does not affect diode.
	FH1100	$1.50 Each	FH1100 Hot carrier schottky detector and mixer diode. C=1pf specs Special $15.00/20. $60/100

Picture	Item #	Price	Description
	27MH	$1.00 Each	27mh choke, 27000µh, Q=60, S.R.F.=.25 MHZ, DC=90 OHMS, 42mA Special $5.00/6
	100uH	$1.00 Each	100µH choke, 5% "Wee-Ductor". 1/2w resistor size. NOS Full leads Special $10.00/12 mix with other wee-ductor ok
	330uH	$1.00 Each	330µH choke, 5% "Wee-Ductor". 1/2w resistor size. NOS Full leads Special $10.00/12 mix with other wee-ductor ok
	1000uF	$.75 Each	1000uF radial lead electrolytic capacitors. Made in Japan. Small size. Special $5.00/10
	MILLER	Various	Miller Coils NOS One of each only! 1459 10.7 mHz Ratio Detector $2.00 Each 1354 19 kHz Locked Osc. MPX $2.00 1357 38 kHz MPX Output Xfmr $2.00 1465WB 10.7 mHz, 900 kHz P/P Discriminator $2.00 R-100 4.5 mHz Ratio Detector $2.00 6271 4.5 mHz Ratio Detector $2.00 6205 4.5 mHz Ratio Detector $2.00 13-W2 1.4-1.6 mHz Output IF $15.00 7122 4.5 mHz Sound IF $2.00 6550 455 kHz Input IF $10.00 5221 4µH 6A. Filament Choke $10.00 5220 8.8 µH Hash Choke $5.00 6527 262 kHz Input IF $7.00 6528 262 kHz Output IF $7.00 6540 262 kHz Output IF $7.00 6554 262 kHz Output IF $7.00 8008 262 kHz Output IF $7.00 7602 Color Service Transformer $2.00 7112-E 4.5 mHz Discriminator $2.00 6195-TV Horz Lin. Control 55 deg Sweep $2.00 7101 4.5 mHz Sound Trap $2.00 7528 44 mHz IF 41.25 mHz trap $2.00 7530 44 mHz Second Video $2.00 181 K-Tran Adaptor Plate $4.00

Picture	Item #	Price	Description
	DPST	$2.50 Each	2 pole, 2 position toggle switch. ½ inch hole. 20A 125-250 VAC Perfect for A+B power.Removed from equipment. Special $20.00/10
	5P2T	$1.00 Each	5 pole, 2 position rotary switch, make-before-break contact. 1/4 inch shaft. Special $10.00/12
	1P3T-CRL	$1.50 Each	Centralab 1 pole, 3 position rotary switch, break-before-make contact. 1/4 inch diameter shaft. $10.00/10
	CER-4-5	$8.00 Each	Imported 4 pole, 5 position non-shorting rotary switch with 6 mm diameter shaft. Ceramic wafer. 1-1/4 inch total width. Special: $28/4 $55/10
	CER-2-11	$8.00 Each	Imported 2 pole, 11 position non-shorting rotary switch with 6 mm diameter shaft. Ceramic wafer. 1-1/4 inch total width. Special: $28/4 $55/10
	HKP	$1.00 Each	Bussmann panel mounted fuse holder. Accepts 3AG, 1.25x.25 inch fuses. Solder terminals.

Picture	Item #	Price	Description
	HHS-9829P	$10.00	H.H. Smith Shrouded safety jack for Simpson Series 7+8. 48 inch lead length. Special $16/2 Large View
	79-127	$10.00	Imported test leads with banana plug on one end, probes with screw on clips on the other end. Special $16/2 Large View
	01927	$17.00	NOS Simpson 01927 Lead Set. Alligator, Mini Banana , in the original package. For Simpson Model 160 and others. Special $30/2
	02055	$17.00	NOS Simpson 02055 Probe Set. Plain, Mini Banana , in the original package. For Simpson Model 160 and others. Special $30/2
	07500	$13.00	NOS Simpson 07500 Lead Set. Alligator, Banana Plug , in the original package. For Simpson Model 260 (series 6 or earlier) and others. Special $25/2

Picture	Item #	Price	Description
	EURO5	$1.00	5 Position European Style Terminal Block. 1.5 inches long. They can be cut apart.
	SPT1182-9BR	$2.00	New Stock! Philmore AC Cord, 9 ft, brown

Johnson Binding Posts

Picture	Item #	Price	Description
	111-0101-001	$1.00	Johnson Banana Jacks, White.
	111-0103-001	$1.00	Johnson Banana Jacks, Black.
	111-0106-001	$1.00	Johnson Banana Jacks, Orange.
	111-0107-001	$1.00	Johnson Banana Jacks, Yellow.

If you see something that you desire, please go to my order info page for further details.