Chapter 6 - How To Interface To Your Linear Amplifier; Ptt Input; Ptt Output; Fet - Apache Labs ANAN-200D User Manual

Chapter 6 – How to Interface to your Linear Amplifier

PTT Input

PTT Output

Most modern Linear Amplifiers have a connection for PTT input for keying the Linear. Apache Transceivers
include a back panel connection for this purpose and it is activated by the PowerSDR software based on menu
preferences. On the ANAN-200D Linear Amplifier PTT OUT it is pin 1 of the AUX I/O Ribbon connector.

FET

The PTT OUT is a common DRAIN 2n7002 type FET transistor as shown in the schematic for the ANAN-200D.
The heavy duty type FET is best used to switch 25vdc and 800ma [or less). Exceeding these values may
damage the PTT OUTPUT circuit.
How to test your PTT Linear Amplifier circuit BEFORE connecting your Apache Transceiver.
Power your Linear, connect the control cable to your linear but do not connect the other end to your
Apache Transceiver
Using a DC Voltmeter, measure the voltage between the center pin and the outer connection of the
cable. This must be less than 25vdc.
Connect a DC Ammeter between the center pin and the exciter connection of the cable. This should
ACTIVATE the Linear Amplifier and give you a clear measurement of the current requirements. The
ANAN-200D PTT circuit should not draw more than 800ma.
If either of these values are out of the required range, then use an external keying interface. There are
many keying interfaces available from many sources such as MFJ, Elecraft, DX Engineering.
Important: Connecting a Linear Amplifier that does not meet the above voltage and current
requirements is likely to cause damage to the Apache Transceiver linear switching transistor and
extreme cases, serious damage to other parts. Damage to the radio caused in this manner is not
covered by Warranty.

Various Linear Amplifier Keying ISOLATION adapters are available

http://www.dxengineering.com/search/product-line/kd9sv-products-sv-kr-keying-relays
http://www.ameritron.com/Product.php?productid=ARB-704
http://www.sultantronics.com/product.html
http://stores.ebay.com/radiodan-w7rf?_trksid=p2047675.l2563

ALC

K2UE has written a helpful document about how he uses ALC with his Apache Transceiver. You can find
the Apache Yahoo Group FILES section:
https://xa.yimg.com/df/apache-labs/ExtALC+Installation+%26+Use.pdf
For more information about suitable couplers from the KC9XG Yahoo Group Files section:
https://xa.yimg.com/df/KC9XG-SDR/PSSamplersCouplers.pdf
Copyright Apache Labs © ANAN-200D 39
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June 22, 2015