RF Gain decrease in sensitivity

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161SM046
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Joined: Tue Dec 31, 2019 2:24 pm

RF Gain decrease in sensitivity

Post by 161SM046 » Sat Feb 01, 2020 1:07 pm

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

kt4lh
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Re: RF Gain decrease in sensitivity

Post by kt4lh » Sat Feb 01, 2020 2:48 pm

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.

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YT5HOK
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Re: RF Gain decrease in sensitivity

Post by YT5HOK » Sat Feb 01, 2020 5:37 pm

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.
Marko

kt4lh
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Re: RF Gain decrease in sensitivity

Post by kt4lh » Sat Feb 01, 2020 9:16 pm

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 ;)

VK3KYY
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Re: RF Gain decrease in sensitivity

Post by VK3KYY » Sat Feb 01, 2020 9:55 pm

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

footloosejava
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Re: RF Gain decrease in sensitivity

Post by footloosejava » Sun Feb 02, 2020 5:23 am

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

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