TK3180 - is it possible to improve front end sensitivity

[g8tzl2004]

I have a TK-3180 which is not as sensitive as some of my other radios...although it is still in spec.

Has anybody ever managed to get better RX sensitivity performance by performing a realignment?

My experience with modern UHF stuff is that the front ends tend to be very broad with no clearly defined front end peak..so small changes in the front end softpots don't make much difference!!

Also I guess the TK3180 is a true wideband 400-470Mhz radio with identical RX performance across the entire band?

Thanks

[TelcomJunkie]

The alignment from the factory is pretty good, though on the TK2180's we noticed some improvement when it was realigned around our frequencies. If it didn't cost you to do, I'd say go ahead.

[g8tzl2004]

Did you change the 5 default test frequencies used for alignment?

The default frequencies cover the entire band and are spread evenly at Low, Center and High values eg 405, 435, 470 MHz

I guess you can just input Low, Center and High values which, say, just cover 440-450MHz?

One issue with the UHF TK3180 is that the front end alignment process involves using default softpot values for some settings and then aligning on other settings..its a bit odd!!

[ramal121]

The TK-3180 uses a varactor tuned front end. You are only setting the steering voltage for that particular test frequency. It is kinda broad and you'll have to move it a ways before you see a drop off. Regardless, your test frequency will have to be centered within the passband. Using evenly spaced test frequencies insures the sensitivity is flat across the entire band coverage.

Why there are default test frequencie values, I don't know. Maybe it make things easier? To be honest, I just don't fool with them. You could take one test frequency and run the numbers up and down and see what is the lowest sinad you get. This will be the best the receiver will do. If the other test frequencies match, leave 'er be. If there is an improvement, then you may want to do all of them.

[g8tzl2004]

Thanks

Do you think it makes sense to change the test frequencies so that they just match the actual operating frequencies.

My guess is that it should make no difference!!