Where to Locate Hard to Find RF Electronic Components

We have all been there.  You found a great schematic for a circuit you want to build.  The only problem is that you are missing a few essential parts.  This is doubly a problem for RF circuits, as many schematics reference parts that haven't been manufactured for decades, and other parts critical to all RF circuits are difficult to track down.

The goal of this post is to help you track down these parts, and understand suitable replacements for components no longer manufactured.  I won't link to eBay auctions or suggest finding items in flea markets.  While both are great places to locate hard to find items, neither can be relied on to have an exact part in stock and readily available at any time.

This is a living post, that I will update over time, and I welcome your input to make this a comprehensive reference.

Transistors

Model	Suitable replacement
2n2222	2n2219 or 2n2222a
2n3553	2n3053 or NTE473

Variable Capacitors

Mouser has a few variable capacitors available that are suitable for RF circuits, manufactured by Sprague Goodman.  Here is a good general purpose cap with a range of 65pf - 320pf.  Other sizes are available that are within typical RF application ranges.  For their full range of products look here.

Crystals

Two common crystal types used in RF electronics are the HC49 and FT243 varieties.  One great place to purchase individual crystals is http://www.af4k.com who has HC49 and FT243 crystals in many values.  I'm also going to violate my no linking to eBay rule, as N4ESS has an eBay store with a huge stock of HC49 crystals in interesting values.

50 Ohm Resistors

50 ohm resistors are great for making dummy loads.  You can purchase high wattage 50 ohm resistors from Jameco.  Here are two that are particularly useful:
Resistor Metal Oxide 50 Ohm 5% 5W
Resistor, 15 Watt, 50 Ohms

Ferrite Torroids

Amidon manufacturers ferrite torroids in a variety of useful ranges for RF circuits.  You can purchase these torroids on Universal Radio or direct from Amidon.  Some schematics reference the no longer manufactured 63 mix, such as the FT 37-63.  The 67 mix has replaced this, so look for FT 37-67 instead.

Other Links

Readers sometimes write in with additional suggestions on places to find RF components.  This is a listing of sites that I have not personally shopped at, but may be a great resource for parts.

> Kits and Parts for toroids and other component needs.
> Fair Radio Sales for many RF components.  They also have an eBay store linked from their site.
> Dan's Small Parts and Kits recommended by a reader for RF parts.
> BG Micro recommended by a reader for RF parts.
> 3rd Planet Solar / KC9ON recommended by a reader for RF parts.
> RF Parts Company recommended by a reader for RF capacitors and transistors.
> All Electronics recommended by a reader for various electronic parts, transistors, switches, etc.

Do you have a website that makes any hard to find components readily available?  Drop me a line so I can add your information to this page.

Last updated: Dec 2, 2019

Posted: Jul 12, 2013