Repeater-Builder Project Information Index

Back to Home Construction Projects
and Articles
Maintained by Robert Meister WA1MIK
Contributions are ALWAYS welcome.

There are other good articles on the Technical Info page

This page has recently been reorganized.
Everything is still here; items just got grouped together by function.

Linear Translator (or linear repeater):

Build a 2M Linear Repeater for all modes! By Mike ZL1BTB
Offsite Link.

Test Equipment or Parts Thereof:

Build an Isolated Tee Sampler for a Bird 43 Wattmeter By Kevin Custer W3KKC
Build an IsoTee Sampler for the Bird from a blank slug!

Build your own Iso-Tee By Ted Bleiman K9MDM (SK)
Build an Iso-Tee from an ordinary T-adapter.

A Photo Tour of a Bird Wattmeter Element By Robert W. Meister WA1MIK
Ever wonder what's inside one of those elements? Read on.

A Poor Ham's Deviation Meter by Robert W. Meister WA1MIK
A theory and practice article on measuring deviation of FM transmitters.

Build Youself a Service Monitor? Well, sort of By Tom Alldread VA7TA
A simple deviation monitor circuit used with a scanner receiver.

A purpose-built Motrac Metering set By Robert W. Meister WA1MIK
I needed to tune a Motrac-based Compa-station but had no official metering set. I had a meter; I bought everything else. You can modify the design to suit your needs.

RF: Amplifiers, Antennas, Duplexers/Filters, Preamps:

Additional Construction Project info can be found on the Antenna Systems page.

Multi-Element Exposed Dipole for 2 Meters By W2EWY & WB2ICP
A good exposed Four-Bay Dipole Array construction project.

Retuning a Stationmaster type antenna By Jim Barbour WD8CHL

Omni-Gain Collinear Repeater Antenna Construction Project By Mike Collis WA6SVT
A great 144 to 1300 MHz antenna project - and there are followup articles on the Antenna Systems page at this web site.

Build a Rugged Half-Wave Coaxial Antenna Coaxial sleeve dipole antenna (offsite link)

Duplexer coupling loops and how they affect performance By Kevin Custer W3KKC
An analysis of factory-built vs home-built loops.

Someone say "6 meter duplexer"? By Jeff DePolo WN3A
A comprehensive conversion of a lowband pass cavity to band-pass band-reject.

Heliax 6 Meter Filter construction article By Robert W. Meister WA1MIK
A comprehensive filter construction article using 1-5/8 inch hardline.

Build a set of CATV Hardline Matching Stubs By Kevin Custer W3KKC

Build a Band Pass-Band Reject Two Meter Duplexer From the W1GAN article in the July 1972 QST

Build a good quality GaAs FET Preamp By Kevin Custer W3KKC
For 2 meters, 220 and 440.

Combining a VHF voice repeater and a digipeater 500 kB PDF file by Eric Grabowski KH6CQ
Share one antenna and feedline by adding some filtering and a combiner.

Audio: Amplifiers, Filters, Limiters:

Build an audio buffer amplifier By Kevin Custer W3KKC
Kick the audio in the butt.

A simple audio mute circuit 20 kB PDF file
If you're using discriminator audio and need to mute it, this circuit will do the job.

A squelch-controlled audio amplifier 15 kB PDF file
This combines the functionality of the LM386 amplifier and a mute circuit. Originally designed for the GE Phoenix radios. It used unmuted audio from the top of the volume control, and a COS signal that goes high to unmute the amplifier.

PL-CG (CTCSS) Filter Construction Projects Build several PL (CTCSS) Filters!

Audio Buffer and De-Emphasis circuit By Lou Harris N1UEC (offsite link)
Use this circuit after a repeater receiver to de-emphasize the audio going to your controller.

Pre- and De-Emphasis circuit component values By Oliver Buland W9ZGS
Pre-calculated common component values.

An Audio Equalizer for Communications Use 234 kB PDF file by Robin Rumbolt WA4TEM
A five-band audio equalizer.

Audio Limiter for NBFM By Kevin Custer W3KKC
A hard audio limiter like you'd use for broadcast audio.

Power Supplies and Modifications:

A 13.8v 40a switching power supply 1.2 MB PDF file by Manfred Mornhinweg XQ2FOD
This switcher is RF-quiet from 50 kHz to over 40 MHz and is over 85% efficient.

The Daiwa PS-304 power supply gets Anderson PowerPole Connectors By Kyle Yoksh KØKN
A step-by-step procedure that increases the usability of a good power supply.

Use an Astron power supply remotely? Look here! Don't run to the repeater site to reset that Astron anymore! (scroll down to the Reset Circuits)

Repeater Controllers and Interfaces:

StarTech CM108 based USB sound adapter conversion article By Kevin Custer W3KKC
This is for AllStar (Asterisk) VoIP.

Generic CM108 based USB sound adapter conversion article Author unknown - likely Steve RoDgers WA6ZFT
This is for AllStar (Asterisk) VoIP.

Basic Stamp 1 and 2 Repeater Controller construction projects By Roger Cameron NØYOX
Inexpensive repeater controllers using the Basic Stamp.

The KE4JFV Repeater Controller Rich Wilcox's repeater controller files as a 50 kB ZIP file.

The VK5DJ Repeater Controller John Drew's repeater controller web site (offsite link).

Build a Two Channel Signal to Noise Voter From the WB2WHC article in October 1992 QST.

A simple Echolink interface By Matt Krick K3MK
Easily constructed with about $10 in parts from Radio Shack. Should work with any radio.

A VHF/UHF/LINK repeater interface/controller 239 kB PDF file
This is a set of nearly identical schematics for circuitry used to provide cross-band inter-agency communications.

The C.A.R.S. Repeater Controller 1.5 MB PDF file. Scanned by Chuck Kelsey WB2EDV. Cleaned up by Bob WA1MIK.
This is the scanned documentation for the Crawford (PA) Amateur Radio Society repeater controller, circa 1987. Probably not available any more.

RPT81 Repeater Controller by W8SBD 685 kB PDF file. Scanned by Eric K8OHZ, cleaned up by Bob WA1MIK.
This was a full-featured repeater controller circa 1996. Probably not available any more.

Repeater Controller by WB6JHQ
This was a full-featured repeater controller in the 1980s and 1990s. Not available any more. This is all that was provided to us by several people.

Useful, Small, and Handy Repeater Circuits:

The Repeater Builder's Friend By Matt Krick K3MK
A device to help to you fix your repeater or program your controller.

Build a telephone line filter that doubles as a lightning protector By Kevin CusterW3KKC
A phone line filter and protector.

A Phone Line Busy Sensing Circuit By Monte Smith, WDØDIR (from ACC Notes, April, 1986)
If you need to share a phone line between your home and a repeater, here's how.

A Push To Talk Delay Circuit By Kevin Custer W3KKC
For ACC controller users.

A COR Hang Timer Circuit By Kevin Custer W3KKC
A simple controller of sorts.

Build a simple COS detector circuit By Kevin Custer W3KKC
For creating a COS signal on radios that don't have one.

Analog noise squelch By Kevin Custer W3KKC
A quality COS logic interface with a professional printed circuit board.

Analog noise squelch and CTCSS decoder By Kevin Custer W3KKC
A quality COS and CTCSS (PL) logic interface with professional printed circuit board.

The Jet Propulsion Laboratory's "Smart VOX" By Randy Hammock KC6HUR and Jan Tarsala WB6VRN

A Crystal Heater construction project By Bob Dengler NO6B
Make that crystal stable.

CH-25 Crystal Heater Kit By Kevin Custer W3KKC
As above with professional circuit board.

A High Performance DTMF Decoder Simplifies Control of Remote Base Stations 156 kB PDF file by Eric Grabowski WA8HEB
From October 1985 QEX

A Tone Beep Keyer for Repeaters 98 kB PDF file by Art Gentry W6MEP (Reprinted from May 1974 QST)
Obtain an Audible Indication of Off-Frequency Operation.

Kenwood COR PTT Buffer Circuit by Robert Meister WA1MIK
Turns a 5V active-low COR signal coming out of a Kenwood TK-7180 (VHF) or TK-8180 (UHF) radio into an active-low open-collector PTT signal suitable for driving a Micor repeater.

Fan Controllers for Radios and Repeaters:

A Simple Repeater Fan Controller 18 kB PDF file by Robert Shepard KA9FLX

A Repeater Fan Controller using a 556 IC 17 kB PDF file by George Henry KA3HSW
This is a follow-up to the above with a modification to use a single 556 chip.

A Current-Sensing Fan Controller by Willie Barnett N1NKM
This circuit is installed inside a linear power supply and adjusts the fan speed based on the current that's being drawn by the radio, so the fan runs faster when the radio is transmitting. Several alternate (and untested) designs are also provided.

A Temperature-Controlled Radio Cooling Fan by John Haserick W1GPO
John used a commercially available temperature controller / thermostat to operate a fan under his 6-meter radio.

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See the Contact Information on this site's main index page.

This web page, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors. All Rights Reserved, including that of paper and web publication elsewhere.

	Build an Isolated Tee Sampler for a Bird 43 Wattmeter By Kevin Custer W3KKC Build an IsoTee Sampler for the Bird from a blank slug!
	Build your own Iso-Tee By Ted Bleiman K9MDM (SK) Build an Iso-Tee from an ordinary T-adapter.
	A Photo Tour of a Bird Wattmeter Element By Robert W. Meister WA1MIK Ever wonder what's inside one of those elements? Read on.
	A Poor Ham's Deviation Meter by Robert W. Meister WA1MIK A theory and practice article on measuring deviation of FM transmitters.
	Build Youself a Service Monitor? Well, sort of By Tom Alldread VA7TA A simple deviation monitor circuit used with a scanner receiver.
	A purpose-built Motrac Metering set By Robert W. Meister WA1MIK I needed to tune a Motrac-based Compa-station but had no official metering set. I had a meter; I bought everything else. You can modify the design to suit your needs.

	Multi-Element Exposed Dipole for 2 Meters By W2EWY & WB2ICP A good exposed Four-Bay Dipole Array construction project.
	Retuning a Stationmaster type antenna By Jim Barbour WD8CHL
	Omni-Gain Collinear Repeater Antenna Construction Project By Mike Collis WA6SVT A great 144 to 1300 MHz antenna project - and there are followup articles on the Antenna Systems page at this web site.
	Build a Rugged Half-Wave Coaxial Antenna Coaxial sleeve dipole antenna (offsite link)
	Duplexer coupling loops and how they affect performance By Kevin Custer W3KKC An analysis of factory-built vs home-built loops.
	Someone say "6 meter duplexer"? By Jeff DePolo WN3A A comprehensive conversion of a lowband pass cavity to band-pass band-reject.
	Heliax 6 Meter Filter construction article By Robert W. Meister WA1MIK A comprehensive filter construction article using 1-5/8 inch hardline.
	Build a set of CATV Hardline Matching Stubs By Kevin Custer W3KKC
	Build a Band Pass-Band Reject Two Meter Duplexer From the W1GAN article in the July 1972 QST
	Build a good quality GaAs FET Preamp By Kevin Custer W3KKC For 2 meters, 220 and 440.
	Combining a VHF voice repeater and a digipeater 500 kB PDF file by Eric Grabowski KH6CQ Share one antenna and feedline by adding some filtering and a combiner.

	Build an audio buffer amplifier By Kevin Custer W3KKC Kick the audio in the butt.
	A simple audio mute circuit 20 kB PDF file If you're using discriminator audio and need to mute it, this circuit will do the job.
	A squelch-controlled audio amplifier 15 kB PDF file This combines the functionality of the LM386 amplifier and a mute circuit. Originally designed for the GE Phoenix radios. It used unmuted audio from the top of the volume control, and a COS signal that goes high to unmute the amplifier.
	PL-CG (CTCSS) Filter Construction Projects Build several PL (CTCSS) Filters!
	Audio Buffer and De-Emphasis circuit By Lou Harris N1UEC (offsite link) Use this circuit after a repeater receiver to de-emphasize the audio going to your controller.
	Pre- and De-Emphasis circuit component values By Oliver Buland W9ZGS Pre-calculated common component values.
	An Audio Equalizer for Communications Use 234 kB PDF file by Robin Rumbolt WA4TEM A five-band audio equalizer.
	Audio Limiter for NBFM By Kevin Custer W3KKC A hard audio limiter like you'd use for broadcast audio.

	A 13.8v 40a switching power supply 1.2 MB PDF file by Manfred Mornhinweg XQ2FOD This switcher is RF-quiet from 50 kHz to over 40 MHz and is over 85% efficient.
	The Daiwa PS-304 power supply gets Anderson PowerPole Connectors By Kyle Yoksh KØKN A step-by-step procedure that increases the usability of a good power supply.
	Use an Astron power supply remotely? Look here! Don't run to the repeater site to reset that Astron anymore! (scroll down to the Reset Circuits)

	StarTech CM108 based USB sound adapter conversion article By Kevin Custer W3KKC This is for AllStar (Asterisk) VoIP.
	Generic CM108 based USB sound adapter conversion article Author unknown - likely Steve RoDgers WA6ZFT This is for AllStar (Asterisk) VoIP.
	Basic Stamp 1 and 2 Repeater Controller construction projects By Roger Cameron NØYOX Inexpensive repeater controllers using the Basic Stamp.
	The KE4JFV Repeater Controller Rich Wilcox's repeater controller files as a 50 kB ZIP file.
	The VK5DJ Repeater Controller John Drew's repeater controller web site (offsite link).
	Build a Two Channel Signal to Noise Voter From the WB2WHC article in October 1992 QST.
	A simple Echolink interface By Matt Krick K3MK Easily constructed with about $10 in parts from Radio Shack. Should work with any radio.
	A VHF/UHF/LINK repeater interface/controller 239 kB PDF file This is a set of nearly identical schematics for circuitry used to provide cross-band inter-agency communications.
	The C.A.R.S. Repeater Controller 1.5 MB PDF file. Scanned by Chuck Kelsey WB2EDV. Cleaned up by Bob WA1MIK. This is the scanned documentation for the Crawford (PA) Amateur Radio Society repeater controller, circa 1987. Probably not available any more.
	RPT81 Repeater Controller by W8SBD 685 kB PDF file. Scanned by Eric K8OHZ, cleaned up by Bob WA1MIK. This was a full-featured repeater controller circa 1996. Probably not available any more.
	Repeater Controller by WB6JHQ This was a full-featured repeater controller in the 1980s and 1990s. Not available any more. This is all that was provided to us by several people.

	The Repeater Builder's Friend By Matt Krick K3MK A device to help to you fix your repeater or program your controller.
	Build a telephone line filter that doubles as a lightning protector By Kevin CusterW3KKC A phone line filter and protector.
	A Phone Line Busy Sensing Circuit By Monte Smith, WDØDIR (from ACC Notes, April, 1986) If you need to share a phone line between your home and a repeater, here's how.
	A Push To Talk Delay Circuit By Kevin Custer W3KKC For ACC controller users.
	A COR Hang Timer Circuit By Kevin Custer W3KKC A simple controller of sorts.
	Build a simple COS detector circuit By Kevin Custer W3KKC For creating a COS signal on radios that don't have one.
	Analog noise squelch By Kevin Custer W3KKC A quality COS logic interface with a professional printed circuit board.
	Analog noise squelch and CTCSS decoder By Kevin Custer W3KKC A quality COS and CTCSS (PL) logic interface with professional printed circuit board.
	The Jet Propulsion Laboratory's "Smart VOX" By Randy Hammock KC6HUR and Jan Tarsala WB6VRN
	A Crystal Heater construction project By Bob Dengler NO6B Make that crystal stable.
	CH-25 Crystal Heater Kit By Kevin Custer W3KKC As above with professional circuit board.
	A High Performance DTMF Decoder Simplifies Control of Remote Base Stations 156 kB PDF file by Eric Grabowski WA8HEB From October 1985 QEX
	A Tone Beep Keyer for Repeaters 98 kB PDF file by Art Gentry W6MEP (Reprinted from May 1974 QST) Obtain an Audible Indication of Off-Frequency Operation.
	Kenwood COR PTT Buffer Circuit by Robert Meister WA1MIK Turns a 5V active-low COR signal coming out of a Kenwood TK-7180 (VHF) or TK-8180 (UHF) radio into an active-low open-collector PTT signal suitable for driving a Micor repeater.

	A Simple Repeater Fan Controller 18 kB PDF file by Robert Shepard KA9FLX
	A Repeater Fan Controller using a 556 IC 17 kB PDF file by George Henry KA3HSW This is a follow-up to the above with a modification to use a single 556 chip.
	A Current-Sensing Fan Controller by Willie Barnett N1NKM This circuit is installed inside a linear power supply and adjusts the fan speed based on the current that's being drawn by the radio, so the fan runs faster when the radio is transmitting. Several alternate (and untested) designs are also provided.
	A Temperature-Controlled Radio Cooling Fan by John Haserick W1GPO John used a commercially available temperature controller / thermostat to operate a fan under his 6-meter radio.