new scope capabilitys

[m3vuv]

Hi all,ive just brought one of these cheap ,Hewlett Packard HP54503A 500MHz 4 Channel Digitizing Oscilloscope, just wondered if it will be capable of doing measurements on a 70cm tx/rx?. tia

[bob91343]

What are you trying to measure?

[m3vuv]

nothing at 70 cms,ive a deaf radio on 2mtrs ,i want to look at the rx signals and trace them,my other scope is 50 meggs bandwith so wondered if the new one is capable of doing this at 145 meggs.

[BrokenYugo]

Google says it's not a true 500MHz, in that it will only handle that as a repetitive signal. So I guess it would work fine for usual inject a signal and see where it stops sort of troubleshooting.

[bob91343]

I don't know that model.  I have a 54542A that works fine well past its claimed limit of 500 MHz.  In fact I measured around 650 MHz bandwidth, very high for what I do.

Having said that, it's seldom necessary to have a wide bandwidth scope to troubleshoot a receiver.  You put a signal in and first see if you have a corresponding IF signal.  If not, the problem is near the front end.  If so, it's later in the chain.  Those radios are almost always at least double conversion so there is a second mixer to investigate.

[max-bit]

As the oscilloscope has a 500 MHz band, it measures up to about 500 MHz (usually with a decrease of -3dB) but this is not a rule.

[MF-jockey]

The probe plays an important role.
There are also nice videos from Dave

active probes

[radiolistener]

At 400-500 MHz it's better to not use probes, but use RF connectors with coax cable. Because probes are working good bellow 100-200 MHz max.