neazoi
Advanced Member level 6
Hi I would like to connect a Tektronix 491 spectrum analyzer and an HP 5245L frequency counter to the same source, so that I can measure it's frequency and at the same time see it's signal in tha SA.
With the available equipment limitation here, I am thinking of connecting them with a single cable and BNC T adapters. Note that I am only interested in HF <30MHZ measuring.
BUT, between the counter and the spectrum analyzer a huge 60dB 50 ohm attenuator will be used.
The input signal to be measured, will arrive at the T adapter and will reach the counter unattenuated. Then it will also pass through the T adapter and reach the attenuator. After the attenuator, the signal will reach the SA.
The attenuator ensures that the SA will not get overloaded or damaged, by the usually higher level signals I encounter in HAM radio (and that are required by this old counter anyway). I am talking about oscillators and other low power RF blocks, not high power amplifiers.
I am thinking that because of the very large attenuator, the SA will be happy and it will mostly see a 50 ohm at it's input, no matter if the counter is connected through the attenuator in parallel with it.
Will that work?
Note that this old SA is only able to do relative measurements, so a degree of inacuracy (as long as it is kept consistent) is tollerated for amateur use.
With the available equipment limitation here, I am thinking of connecting them with a single cable and BNC T adapters. Note that I am only interested in HF <30MHZ measuring.
BUT, between the counter and the spectrum analyzer a huge 60dB 50 ohm attenuator will be used.
The input signal to be measured, will arrive at the T adapter and will reach the counter unattenuated. Then it will also pass through the T adapter and reach the attenuator. After the attenuator, the signal will reach the SA.
The attenuator ensures that the SA will not get overloaded or damaged, by the usually higher level signals I encounter in HAM radio (and that are required by this old counter anyway). I am talking about oscillators and other low power RF blocks, not high power amplifiers.
I am thinking that because of the very large attenuator, the SA will be happy and it will mostly see a 50 ohm at it's input, no matter if the counter is connected through the attenuator in parallel with it.
Will that work?
Note that this old SA is only able to do relative measurements, so a degree of inacuracy (as long as it is kept consistent) is tollerated for amateur use.
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