When connecting an antenna I heard noise increase. However on the higher bands I needed to open the volume fully to hear it. Weak stations were hard to copy.
So I build a preamp. It is placed after the band filters. Before the first mixer.
I used the following amplifier as base http://www.hamlan.org/tech/w7iuvpreamp/
Difference is that I use a 2N2219. I use relays to bypass the filter when needed.
I get 12 db gain out of it when terminated with 50 Ohm. That is enough for most bands. For 12 and 10 meter It is probably enough. I need to wait for weak signals to appear.
I have tried it on 40 meter. No signs of intermodulation.
This is close up of the panel. The awful stickers will be replaced soon.
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