#658

Episode 658
Using the HP8921a to measure receiver sensitivity. The spec is less than .016uV 12dB SINAD
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[@acestudioscouk-Ace-G0ACE]

This is so nicely explained, thank-you.

[@bobkozlarekwa2sqq59]

Overall not a bad deal for a disposable radio thanks for all your hard work and happy new year

[@johnbigbooty]

Thank you so much. I have the HP8920A and the IFR1200S. You did a great job explaining this!

[@TingILi]

Hi did you want to sell your IFR1200S? my one has some issues

[@nomadiclog]

Such a great channel. I admire these kind of efforts. Please keep it up

[@IMSAIGuy]

Thank you very much!

[@eswnl1]

On the web, SINAD is described as the ratio of the POWER, not voltage. So it would be 10log..

[@IMSAIGuy]

you are right it is power, if you make the measurements in power then it is 10log, if you make them in volts, then 20log. this is V^2 which is power www.analog.com/media/en/training-seminars/tutorials/MT-003.pdf

[@eswnl1]

@@IMSAIGuy I'm guessing that which ever method you choose, you will arrive at the same answer.

[@PapasDino]

If a rig is really hot you may have to turn off the squelch to complete the measurement; luckily here it's set below the 12 dB SINAD point. Without the squelch you'd be able to measure the MDS. Did you chart out the frequency pattern of the 16 channels? I'm guessing this was specifically made for the 440-450 MHz simplex band.

[@kuyavenzinfovlog]

great video sharing my friend

[@IMSAIGuy]

Thank you

[@edschaff6291]

The signal your inputing to the radio is 1000HZ is that at any certain RF frequency OR Only the 1000Hz AUDIO signal ??

[@IMSAIGuy]

the RF carrier is FM modulated at 1000Hz

[@wb8vqv]

So how do you know how much 1KHz audio with the radio volume control to send back into the service monitor?

[@dennisqwertyuiop]

I use a motorola sinad meter,for these tests,1000hz tone

[@venkatnarayanaiah5039]

How test rx distortion and audio out out

[@IMSAIGuy]

The HP8920 and HP8921 have both tx and rx distortion measurements. The user manual shows how to do both of those measurements. The Rx distortion is very similar to SINAD you just press a different button. Tx is a bit more complicated and you need to connect the microphone input to the HP device so it can transmit the audio tone.

[@jdmccorful]

Interesting, I am guessing that you can do the same with an FM receiver.???

[@IMSAIGuy]

any receiver