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RF Gain decrease in sensitivity
Posted: Sat Feb 01, 2020 1:07 pm
by 161SM046
Is there somewhere an option to reduce the sensitivity of the receiver to VHF, something like RF GAIN? The problem appears when connected to a directional antenna .. the receiver is choking
Re: RF Gain decrease in sensitivity
Posted: Sat Feb 01, 2020 2:48 pm
by kt4lh
Could look into getting an "intermod" filter or some other kind of inline filter, just keep in mind that they are not going to be dual band, and might not fix the issue.
Honestly HTs aren't designed to be used on high gain antennas, if you need to use it as a base frequently maybe you should look into a mobile rig.
Re: RF Gain decrease in sensitivity
Posted: Sat Feb 01, 2020 5:37 pm
by YT5HOK
Radioddity GD-77 has simple direct conversion receiver, as opposed to more complicated and more expensive superheterodyne one.
Direct conversion is infamous for going "deaf" when overwhelmed with RF signals, as is for receiving (opening squelch) for all kinds of interference.
So, as said, it is not a good choice for directional antenna.
Re: RF Gain decrease in sensitivity
Posted: Sat Feb 01, 2020 9:16 pm
by kt4lh
YT5HOK wrote: ↑Sat Feb 01, 2020 5:37 pm
So, as said, it is not a good choice for directional antenna.
Not a good choice for an antenna that has any gain
Re: RF Gain decrease in sensitivity
Posted: Sat Feb 01, 2020 9:55 pm
by VK3KYY
The RF chip (AT1846S) does not have an RF gain control.
Well, if it does, there is nothing in the data sheet about it.
https://github.com/rogerclarkmelbourne/ ... de-1.4.pdf
Re: RF Gain decrease in sensitivity
Posted: Sun Feb 02, 2020 5:23 am
by footloosejava
https://forums.radioreference.com/threa ... ed.394672/
May be of interest.
And if that can solve the crackle when moving, all the better.
Post # 14 in that conversation has some hope.
https://forums.radioreference.com/threa ... st-3191878