Technical Support - Repairs - Software - Manuals - Tech Tips - Legacy
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This is a compilation of advice, tips and miscellaneous info from the Alpha lab.

Alpha 9500 fault codes can be found HERE.

As you know "Cleanliness is next to...", so without further ado:
Keep your Alpha Clean!

Should I leave my Amp on all the time? No (click here for an in depth explanation)

Alpha Amplifier Keying Specs

The above "QSK amp connections" pages are not meant to include all brands/models of radios. They are alternative ways to key Alpha amplifiers from SOME types of radios. In all cases it is possible to follow the radio manufacturers' instructions in the radio manual for amplifier keying connections.

Remote Antenna Switches recommended for use with Alpha's DAS

Wiring Remote Switches Into The Alpha DAS

Legacy Amplifier Specifications

Alpha Amplifiers Around the World

K4XL's on-line Archive of Legacy Equipment Manuals

ALPHA 78, 76A series, and 374A Low Drive Modification

1979 WARC-Band Operation and Modification

Replacement Blower instructions for ALPHA 87A (zipped pdf file)
Replacement Blower for ALPHA 86, 78, 76A series, and 374A

Bandpass Adjustment Procedure (Alpha 78 / 374A )

Bandpass Adjustment Procedure (Alpha 374)

160m Modification for ALPHA PA-77 (not Dx or Sx)

PA70-V Bandswitch wiring and supplier info.

Alpha Amplifier Advertisements Through The Years

Below you'll find some questions and answers put together by our techs.

- What is the best way to use the 87A AlphaMax functions?
When the new (since 1999) AlphaMax (Autotune) firmware is installed in the 87A, the TUNE and LOAD LEDs will blink to indicate what the AlphaMax program would do if it was enabled.

An addendum to the 87A manual was included with AlphaMax kits thatwere installed in the field, or you can download a copy of the new version of the 87A manual (with instructions for using AlphaMax) from our web site: here

You should tune up the amp with your antennas on each band/segment andsave the settings in USER memories. When changing bands the 87A first goes to the USER memory setting. If further tuning is needed it willmake the adjustments if the Autotune mode (AlphaMax) is enabled. If it is not enabled, the TUNE and/or LOAD LEDs will blink to indicatewhat direction those would be moved.

If it is not in Autotune and the user settings are not at all close to desirable, it will fall back to factory-saved default settings (for a 50 ohm load) and the DEFAULT LED will light solid. If that is not close enough to get normal output with the current load, the amp will get a Fault 17.

The Autotune function is enabled by pressing the LOAD^ and ENTER buttons at the same time. The DEFAULT LED will flash when Autotune is enabled and the amp is in operate and warmed up.

Please note that the TUNE meter is a rough indicator to allow the amp to be tuned with low drive levels so that it is close to being set for 1500w output. Once you increase the drive and are close to 1500w out, fine tune by adjusting the TUNE and LOAD controls for maximum output at the drive level you are at. This should correspond to a dip in the plate current. The TUNE LED may be a number of LEDs off center to either side. The most useful multimeter parameter to monitor when transmitting is the Ip (plate current), also watching the Ig (grid current).

The TUNE meter is calibrated on 20m when the amp is tuned up for 1500w out, with new tubes. As the tubes age, it will indicate off center a bit. Line voltage that is not at the nominal value for each range (200, 220 or 240v) may also affect the TUNE calibration.

Since the 87A has memories that should be saved for the tuneup settings for each band segment, the TUNE meter isn't really as useful as it is with a manually tuned amp (Alpha 89/91B/99)

- How do I key the Alpha 99/91B with an Icom 746/756 radio? The Alpha 99/91B has 25vdc @ 7ma at the RELAY jack. This is within the specs of the OMR-109 relay in the Icom radios, although Icom says it is rated for 16v/500ma. The problem is not the voltage rating, but the spec of the relay for operations per minute. With NO electrical load on the contacts, it is rated for 300 operations per minute, or about 10 wpm QSK CW. Faster than this will cause it to fail prematurely. When there is any electrical load on the contacts, the operations per minute rating is less. NOTE: Alpha 99 amplifiers manufactured after 15 DEC 2002 have 12vdc @ 7ma on the RELAY jack.

This web page explains it very well: Icom FAQ.

- What does the TUNE function of the multimeter indicate? The TUNE function is a 'gain' meter. It indicates that the amplifier is tuned to good efficiency, and is calibrated to be in the center at 1500w out on 20m. The TUNE meter may be a few LEDs off center on bands other than 20m. It should not be used as the last indication that the amplifier is tuned correctly.

Finish tuning by adjusting the TUNE control for peak output, which should also produce a dip in Ip. Monitor the RF output and Ip.

- Should I Turn My Amp Off or Leave It On? Vacuum tubes are like incandescent light bulbs, the filament inside is heated and has a finite life. Two things make them wear out; the initial stress of the current surge when turning them on (that is usually when a light bulb burns out), and the time that they are left on.

Alpha amps reduce the initial current surge stress by using a small resistor in series with the tube filaments.

It is a balance between turning the tube filaments on off on off, or letting them run for hours on end. If you will be using the amp again on the air within an hour or so, leave it on. If it will be 2 hours or longer, turn it off between operating sessions.

- Why don't I see my typed characters when using Hyperterminal to communicate with the 87A? The makers of Hyperterminal, Hilgraeve, have an updated version that fixes this problem. Download a free copy from their web site:Hilgraeve, Inc.