Topband: Slightly OT - amplifier noise

[Michael Tope]

Roger,

When you checked for increased noise on 10 and 15 meters, did you have 
your radio set for maximum sensitivity and were the main and AUX input 
ports of the MFJ-1025 terminated with 50 ohms (or at least not connected 
to any outside antenna)?

73, Mike W4EF.........

On 3/17/2020 11:18 AM, Roger Kennedy wrote:
> Having just read some of these posts, I just did a few tests on my MFJ-1025.
> (bought mine second-hand very cheap - a lot of people buy these thinking
> they will get rid of any noise!)
>
> I modified it to become a 1026 . . . you definitely need the extra pre-amp
> for the "Noise Antenna", especially on 160m - fortunately they use the same
> PCB for both versions, so you can easily add their extra preamp circuit
> design on the PCB.
>
> I normally only use mine on 160m . . . but just did a test on 15m & 10m . .
> . it adds no noticeable noise whatsoever !
>
> So I think the OP's must be faulty . . perhaps powering it by a noisy PSU?
>
> Roger G3YRO
>
>
>
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