VHF Engineering Information Index

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VHF Engineering Equipment

Compiled, HTML'd and Maintained by Mike Morris WA6ILQ
Formerly Maintained by Robert Meister WA1MIK

This page lists the available documentation for equipment formerly made by the "VHF Engineering" company of Binghamton, New York, USA, commonly known as "VHFE".
There is a "VHF Engineering" located in Cannock, Staffordshire, UK that is totally unrelated to the USA company.

Donations of information, especially PDFs of manuals that we don't have would be greatly appreciated.
We can also scan paper manuals... just contact the page maintainer...
Your page maintainer has very little personal knowledge of this equipment.

Assembly and Instruction Manuals:

BLC 2-70 and 10-70 VHF Amplifiers 781 kB PDF, manual number #5011215 Rev 00
The 10-70 is a 10 watts in, 70 watts out 2m amplifier, the 2-70 has an extra stage and is the 2 watts in, 70 watts out version. It can be built as a class C (i.e. FM) amplifier or as a class AB (i.e. SSB) amplifier.
If you exceed the rated input power you WILL blow up the input stage. Parts are getting hard to find.

BLC 10-150 and 30-150 VHF Amplifiers 81 kB PDF, donated by Steve N1UIR
The 10-150 is a 10 watts in, 150 watts out 2m amplifier; the 30-150 is a 30 watts in, 150 watts out amplifier. They are similar to the BLC 2-70 and 10-70 amps above. We only received the schematic and parts list.

BLD-220 power amplifier 534 kB PDF, manual number 5011225
220 MHz amplifier

COR-2 module 148 kB PDF, manual number 5011001
This module implements the carrier delay timer (sometimes called the hang-in timer) and the timeout timer.

COR-2 module notes 312 kB PDF, manual number 5011001 Rev.00
The above manual with some hand-drawn notes on the schematic

CW Identifier 403 kB PDF, manual number 5011002
Note that the VHFE IDer produces a square wave output that needs to be filtered before injecting into a transmitter. DO NOT use this IDer on a transmitter that has no audio filtering before the modulator. With a few mods this unit can serve as an RTTY "whoami" string encoder.

HT-144B Instruction Manual 4.0 MB PDF courtesy of Glenn Petersen KE9QZ (includes service info)

PA-144/15, PA-144/25, PA-220/15, PA-450/10 309 kB PDF, manual number 50100807
This board could be built as a 15 or 25 watt 144 MHz amplifier, a 15 watt 220 MHz amplifier, or a 10 watt 432-450 MHz amplifier.

PS-3A Power Supply documentation 110 kB PDF, manual number 5010203

PS-15C Power Supply Instruction Manual 1.9 MB PDF, manual number 5010103

PS-25C Power Supply Kit Instruction Manual 700 kB PDF
A cleaner version can be found here as a 603 kB PDF file.

The VHF Engineering power supplies were based on the NE550 voltage regulator IC instead of the more common "723" chip. As such the schematic and theory sections are applicable to other supplies based on the same chip. These two chips are functionally and pin equivalent but the reference voltage is vastly different, so you can't just swap them without making some resistor divider changes. NE550N chips are getting rare. The article below shows which two resistors need to be changed, along with the IC, to get your VHF Engineering power supply to work with an LM723.

Converting a VHFE power supply to use an LM723 regulator chip by Robert W. Meister WA1MIK
I acquired a nicely made PS-25M (yes it has front-panel meters) that probably came from the factory using the LM723 IC, so the resistor values were already modified. Some other simple wiring changes improved the no-load to full-load regulation.

PS-25M Schematic plus parts list 62 kB PDF, drawn by Bob WA1MIK
For metered supplies with the 723-style regulator. This goes with the above article.

RPT-50, RPT-144, RPT-220, RPT-432 478 kB PDF, manual number 5010901
This is the documentation on the VHFE Repeater

RX-50C, RX-144C, RX-220C, RX-432C 940 kB PDF, manual number 5010305
This is the documentation on the VHFE RX-series 50, 144, 220, and 432 MHz receivers

Synthesizer II 2-meter frequency synthesizer kit 7 MB PDF, manual number 5011204. Donated by Dave Menges WB9TEN
Very similar to one of the GLB Channelizers.

TX-144B, TX-220B 507 kB PDF, manual number 5010602
This is the documentation on the VHFE TX-series 144 and 220 MHz transmitters

TX432 UHF transmitter kit manual 400 kB PDF, manual number 5010604
Started as individual scanned PDF pages, converted to BMPs, turned back into one PDF file.

432 MHz transmitter schematic 340 kB PDF
Hand-drawn schematic (by an unknown person), sent to Repeater-Builder by Martin HB9TZW

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This page originally posted on 20-Jan-2005

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.

Assembly and Instruction Manuals:
	BLC 2-70 and 10-70 VHF Amplifiers 781 kB PDF, manual number #5011215 Rev 00 The 10-70 is a 10 watts in, 70 watts out 2m amplifier, the 2-70 has an extra stage and is the 2 watts in, 70 watts out version. It can be built as a class C (i.e. FM) amplifier or as a class AB (i.e. SSB) amplifier. If you exceed the rated input power you WILL blow up the input stage. Parts are getting hard to find.
	BLC 10-150 and 30-150 VHF Amplifiers 81 kB PDF, donated by Steve N1UIR The 10-150 is a 10 watts in, 150 watts out 2m amplifier; the 30-150 is a 30 watts in, 150 watts out amplifier. They are similar to the BLC 2-70 and 10-70 amps above. We only received the schematic and parts list.
	BLD-220 power amplifier 534 kB PDF, manual number 5011225 220 MHz amplifier
	COR-2 module 148 kB PDF, manual number 5011001 This module implements the carrier delay timer (sometimes called the hang-in timer) and the timeout timer.
	COR-2 module notes 312 kB PDF, manual number 5011001 Rev.00 The above manual with some hand-drawn notes on the schematic
	CW Identifier 403 kB PDF, manual number 5011002 Note that the VHFE IDer produces a square wave output that needs to be filtered before injecting into a transmitter. DO NOT use this IDer on a transmitter that has no audio filtering before the modulator. With a few mods this unit can serve as an RTTY "whoami" string encoder.
	HT-144B Instruction Manual 4.0 MB PDF courtesy of Glenn Petersen KE9QZ (includes service info)
	PA-144/15, PA-144/25, PA-220/15, PA-450/10 309 kB PDF, manual number 50100807 This board could be built as a 15 or 25 watt 144 MHz amplifier, a 15 watt 220 MHz amplifier, or a 10 watt 432-450 MHz amplifier.
	PS-3A Power Supply documentation 110 kB PDF, manual number 5010203
	PS-15C Power Supply Instruction Manual 1.9 MB PDF, manual number 5010103
	PS-25C Power Supply Kit Instruction Manual 700 kB PDF A cleaner version can be found here as a 603 kB PDF file.
The VHF Engineering power supplies were based on the NE550 voltage regulator IC instead of the more common "723" chip. As such the schematic and theory sections are applicable to other supplies based on the same chip. These two chips are functionally and pin equivalent but the reference voltage is vastly different, so you can't just swap them without making some resistor divider changes. NE550N chips are getting rare. The article below shows which two resistors need to be changed, along with the IC, to get your VHF Engineering power supply to work with an LM723.
	Converting a VHFE power supply to use an LM723 regulator chip by Robert W. Meister WA1MIK I acquired a nicely made PS-25M (yes it has front-panel meters) that probably came from the factory using the LM723 IC, so the resistor values were already modified. Some other simple wiring changes improved the no-load to full-load regulation.
	PS-25M Schematic plus parts list 62 kB PDF, drawn by Bob WA1MIK For metered supplies with the 723-style regulator. This goes with the above article.
	RPT-50, RPT-144, RPT-220, RPT-432 478 kB PDF, manual number 5010901 This is the documentation on the VHFE Repeater
	RX-50C, RX-144C, RX-220C, RX-432C 940 kB PDF, manual number 5010305 This is the documentation on the VHFE RX-series 50, 144, 220, and 432 MHz receivers
	Synthesizer II 2-meter frequency synthesizer kit 7 MB PDF, manual number 5011204. Donated by Dave Menges WB9TEN Very similar to one of the GLB Channelizers.
	TX-144B, TX-220B 507 kB PDF, manual number 5010602 This is the documentation on the VHFE TX-series 144 and 220 MHz transmitters
	TX432 UHF transmitter kit manual 400 kB PDF, manual number 5010604 Started as individual scanned PDF pages, converted to BMPs, turned back into one PDF file.
	432 MHz transmitter schematic 340 kB PDF Hand-drawn schematic (by an unknown person), sent to Repeater-Builder by Martin HB9TZW