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. Make 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. The bottom clip is now a copper snap ring.
245uH Ameritron Choke
Frequency M is MHz. Exclusion is just below 11 MHz. 20 MHz also may be a problem. The exact problem depends on how close the choke is to other objects and what those objects are.
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 both ends.
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 $130.
RFC245 TPS4 bundle installed in Clipperton L Dentron
RFC245s or RFC245LL
$75 shipped anywhere in USA. Includes brass hardware and improved base insulator. World shipping is available. email us at
FL2100 plate choke, Amp Supply plate choke, Drake Plate Choke, Dentron Plate Choke, Heathkit Plate Choke
FL2100 replacement, designed here. This choke excludes use on 16 MHz. Unlike the original, this choke allows use on WARC bands.
This choke is 175uH @ 3.5 MHz. It is a superior choke for the SB220 choke, especially if you add 1.8MHz.
Fully tested. 1.2+ amperes DC, 1-30MHz. High temperature ceramic form.
Operation excludes 16 MHz band! In stock for immediate delivery With brass metric inserts $78.00 total includes Priority Mail USPS shipping. Please specify this insert option!
With standard 1/4-20 US imperial machine threads $70.00 total includes Priority Mail USPS shipping. This is the standard choke.
Heathkit SB200 Heathkit SB220 OEM original quality exact electrical copy. Mounts as original Heathkit 45-61 choke
OEM Style PN 45-61 Heathkit Plate Choke on ceramic form
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.
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
We have a large stock of inductors and RF chokes, thousands of different types. Please email for your specific needs.
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.
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:
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.
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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