Electronics > RF, Microwave, Ham Radio

RF amplifier gain

<< < (3/3)

rfclown:

--- Quote from: Joel_Dunsmore on November 20, 2021, 08:16:02 pm ---And, it is entirely possible it's not the fault of the measurement...sometimes you get a bad part.

--- End quote ---

This is true. Dr. Joel is my elder and has more experience than I, but in my experience:
how often have I had a power supply that current limited (or had a control voltage wrong) and thought my gain was low?... many times
how often was I compressing the amp and thought the gain was low?... many times
how often have I have bad cables and thought the circuit wasn't functioning correctly?... many times
how often has it been a bad part?... WAY fewer times than the other above mentioned items

Joel_Dunsmore:

--- Quote from: rfclown on November 21, 2021, 01:33:16 am ---This is true. Dr. Joel is my elder and has more experience than I, but in my experience:
how often have I had a power supply that current limited (or had a control voltage wrong) and thought my gain was low?... many times
how often was I compressing the amp and thought the gain was low?... many times
how often have I have bad cables and thought the circuit wasn't functioning correctly?... many times
how often has it been a bad part?... WAY fewer times than the other above mentioned items

--- End quote ---
Well yes. All those are much more common; along with many others.  The advice of "put a pad on the source, put a pad on the receiver, connect a thru and record the number, put in the amplifier and record the change" is about the most fool-proof way to get a gain number. But remember: “When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.” ~ Arthur Conan Doyle, The Case-Book of Sherlock Holmes.  or, maybe also relevant: if you make some more fool-proof, they'll just make a better fool.

cdev:
If your receiver is on a drone is there any way you can reduce noise, say from motor or other components without adding too much more weight?

Adding an LNA may give you more possibilities if your receiver is receiving just signal, but it will also amplify any noise that is present at the LNA's input. Any detectable noise may even have the effect of desensitizing a receiver. Fairly small bypass capacitors can often work magic with RF noise. Right at its source, ferrite beads may also help.

Navigation

[0] Message Index

[*] Previous page

There was an error while thanking
Thanking...
Go to full version