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IFR-1900 Receive IF Module

Posted: Fri Sep 07, 2018 2:55 am
by SuperLid
I have an analyzer that exhibits low levels. The problem has been isolated to the RX IF block. With no schematics and no support from the manufacturer, I am on my own and going nowhere fast.

Anyone have experience troubleshooting this module at component level?


Re: IFR-1900 Receive IF Module

Posted: Thu May 16, 2019 10:32 am
by clemeth
I have an IFR 1900CSA which had a blown RF Amp on the output of the RF Generator. So called MMIC RF amplifier got fried. Replaced it with a similar device from Mini Circuits and now I'm getting upwards of +10 dBm of signal out.

Re: IFR-1900 Receive IF Module

Posted: Sat Jun 01, 2019 6:35 am
by jry
just to be clear the output device is NOT and MMIC but a discrete device GaAs HFET that needs to have the bias adjusted as part of the replacement.

The output needs to be biased in the linear range in order to correctly pass AM as well as the other complex digital waveforms used in the cell phone testing area.

I have repaired the RX IF as well in the 1900. Non trivial due to the complexity of the module.

The 1900 makes the 1600 look simple because of the changes introduced to support the 1-2Ghz band as well as other features.

The 1900 has a factory calibrated wattmeter that is frequency compensated but you have to manually enter the assumed frequency instead of it taking that directly from the RX screen. ( like later Motorola and HP )