RF Chokes and Inductors

I designed many popular RF chokes used in many commercial amplifiers over the past 40 years. Please check the list below for your needs.  Series resonances will create “no operate” frequencies, so be sure the choke you order is not series resonant on a band you desire.


This is the later 3-section Ameritron plate choke that was originally designed here. We sell correctly-manufactured ceramic core chokes. This choke, or copies of this choke, are widely sold across the Amateur supply chain.

Ameritron RF Plate Choke

245uH Ameritron Choke

This choke comes with two different top lugs. The AL80 AL1200 style with a single short ring lug is CTR part number RFC245s.

The long lug AL811 style choke is RFC245LL.

The choke form is 1″OD, 5-1/2″ long, and tapped 1/4″-20 thread.

Our choke is a carefully manufactured replacement for MFJ-manufactured Ameritron Gen II plate chokes used in post-1990’s Ameritron amplifiers. Our chokes are wound to exacting original specifications with better doping to retain windings. This choke is a direct “better-than-factory” replacement for the MFJ wound 10-15139, 10-15197, or early Prime Instruments chokes used in Ameritron amplifiers. Please consult with us for other applications.

This is our RFC245 plate choke with our TPS4 suppressor installed in a Dentron Clipperton L amplifier. The suppressor and choke bundle price with hardware USA shipped is $100.

RFC245 in Clipperton L Dentron

RFC245 TPS4 bundle installed in Clipperton L Dentron

RFC245s or RFC245LL

$65 shipped anywhere in USA. Includes brass hardware and improved base insulator. World shipping is available. email us to

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Other RF Chokes and Formers

We stock the following standard ceramic forms for chokes:

10″ x 1.25″ x 1/4″-20 thread

5-1/2″ x 1″ x 1/4″-20 thread

4″ x 1-1/4″ x 1/4″-20 thread

2-1/2″ x 3/4″ x #10-32 imperial thread

We also stock the following Delrin spacers and forms:

2-1/4″ x 1″ x 1/4″-20 thread


FL2100 replacement, designed here. Just as with the original FL2100 choke, this choke excludes use on 18.2 MHz. Unlike the original, this choke allows use on 24 MHz.

This choke is 192uH @ 3.5 MHz. It is a superior choke for the SB220 choke, especially if you add 1.8MHz.

FL2100 and Amp Supply choke

Plate choke Amp Supply (6-32 fastener) or Yaesu FL2100 series (metric) high temperature Teflon form

FL2100B FL2100 LK500 HeathKit universal choke. Tapped either metric or imperial thread.

Fully tested. 1.2+ amperes DC, 1-30MHz. High temperature Teflon form.

Operation excludes 18 MHz band!   In stock for immediate delivery $68.00 total includes Priority Mail USPS shipping.

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We have a large stock of inductors and RF chokes, thousands of different types. Please email for your specific needs.



Heathkit SB1000 and Ameritron early AL80A amplifier designed here.


117 µH nominal with series resonances at 19.5 and 27.3 MHz. Nominal diameter is 1″ by 5.5″ long. Tapped 1/4″-20 imperial thread

Standard Radio Frequency chokes single layer and older  direct replacement Heathkit SB-1000 and older AL80A Ameritron plate choke. $42 shipped anywhere in the USA.

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Heathkit SB200 Heathkit SB220 OEM original quality exact electrical copy. Mounts as original Heathkit 45-61 choke



Heathkit 45-61 plate choke

OEM Style PN 45-61 Heathkit Plate Choke on ceramic form

SB200 SB220 Heathkit plate choke

Heathkit replacement chokes ceramic forms


Wound here to original specifications. $49 shipped. Unlimited inventory, although lower terminal design varies. The copper snap ring on right actually has very slightly better characteristics.

Email to Order


Custom high power or high voltage RF chokes available!

Custom RF Chokes

Custom RF chokes and inductors designed and verified to your specifications. $70/hr labor plus materials. Inquire for price.

Example of rewound OEM choke. The damaged choke is frequency swept if possible so an exact electrical duplicate can be made. Otherwise a physical copy is made. Typical cost is $100 plus materials, although individual chokes can be more or less.

We have a large stock of inductors and RF chokes, thousands of different types. Please email for your specific needs.




FL2100 choke before repair/rewind:

NO LONGER OFFERED. We sell a better direct replacement. See page top.

severely burned FL2100 choke

FL2100 plate choke damaged

FL2100 choke after repair/rewind:

Rewound and tested plate choke for FL2100 Yaesu

FL2100 plate choke rewind


Axial lead chokes, pi and solenoid, of various ratings. E-mail with requirements.

2.5mH 250mA for Johnson, Knightkit, Heathkit, and other old tube rigs:

SB200 SB220 FL2100 Henry amplifier Ameritron Dentron Amp Supply Vectronics Boat anchor choke 2.5 mH 1 mH 100uH

2.5mH 250 mA pi wound RF choke

CTR PN RFC25k   $12.00 each
E-mail to order


We have dozens of other RF chokes.

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Edge Wound Inductors and Air Wound Inductors of all sizes. 

Miniductor, edge wound, copper tubing, and high current silver plated custom inductors.

Inquire for pricing and stock.
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