DUPLEXER Tune up on HP8560E & HP8920, Marconi 6200, 2968 + noise source for those without track Gen.

3,443

60 0

2021-08-07に共有

i demonstrate how to tune a Duplexer filter, we adjust it in real time & i show the measurements using four different instruments being a Marconi 6200A Microwave vector scalar analyser, a HP8920 Radio Test Set, a Marconi IFR 2968 Radio Test Set, a HP8560E Spectrum Analyser all of which have tracking generators. I also demo for those whom don't have a tracking generator how an inexpensive EBay Noise Source 100KHz to 4GHz can be used in place of a tracking generator to obtain the same outcome. You will also see in real time how to configure & calibrate the test enviroment & setup measurments by navigating the different methods for each instrument. We Finnish the video with a final check of the RX & TX port isolation where we see the double notch to confirm the Duplexer has been setup correctly. This Duplexer was given to me by a friend whom runs the local Ham Radio repeater network, this duplexer is to be used on a DSTAR Voice Digital Radio Repeater working on 430.450 MHz & 439.450 MHz respectively.

コメント (4)

@Stefan_-qs6tp 2ヶ月前

Hello, nice Video. To measure the Duplexers and tweaking it at the end ist is useful to reduce the resolution bandwidth of the spectrum analyzer to 10kHz or 1 kHz at the end. With 300kHz or 100kHz the dynamic range and noisefloor of the spectrum analyzer is limited to about -65 to -80db. With 1kHz you should measure easy down to -110dB. This is why the other Instruments measure only -40 to -60db here the RBW was set to 1Mhz. Normally you can tweak the duplexes easy over -90dB. Video bandwidth should also set to 10kHz or 1kHz. The Measurement and update rate of the Screen will slowdown but you see the real notching of the duplexer.
@Aligreta 2年前

For me, propper way to tune these duplexers is by means of proper VNA getting S21 and S11 track at same time with at least 100dB dynamic range
@lain4231 1年前

Can this be done using a Marconi instruments 2955b?