Register Account

Login Help

Forum Home - Rules - Help - Login - Forgot Password
Members can access, post and reply to the forums below. Before you do, please first read the RULES.

Two-tone Transmit IMD Test Procedure

Oct 21st 2017, 17:56


Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
The ARRL Lab Test Procedures Manual indicates the the subject measurements are made at one frequency in each band at the manufacturer's maximum rated output power.

My experience with two transceivers from the same manufacturer with several iterations of low-power and high-power modules has shown wild variations in IMD with respect to frequency and/or power level.

Since the published product reviews show only one number for each order I wonder how this number is selected from the test data.

Wes N7WS
Oct 23rd 2017, 12:47


Super Moderator

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
The test procedures manual specifies either the manufacturer's specification for IMD or the maximum PEP rating if the manufacturer does not provide a specification. A measurement is made on each band and the worst case is published.

I'd assume the preference would be to see how well a radio does against a manufacturer's claims of performance.

Zack Lau W1VT
ARRL Senior Lab Engineer

Back to Top


Instragram     Facebook     Twitter     YouTube     LinkedIn