[Hallicrafters] SR-150 Tuning

[John N. Schwartzberg]

>Hey Gang -
>
>I dusted off my radio bench, then the SR-150, to warm up the shack.  I 
>noticed the following while tuning it up on both 20 and 40 meters:
>
>With a resonant antenna load, peaking both the pre-selector tuning and the 
>final output tuning for maximum indication on either an external 
>watt-meter or the internal meter results in relatively low receiver 
>sensitivity.  I can then increase the receiver sensitivity with the 
>pre-selector tuning, but at the expense of output.  The manual includes 
>the following tuning instructions:
>
>"Adjust the RF Level control until a small indication is seen on the 
>S-meter.  In the transmit mode, the S-meter indicates the relative RF 
>voltage.  Adjust the FINAL TUNING control for maximum output and then 
>adjust the PRESELECTOR for maximum output indication.  Adjust the RF LEVEL 
>control as required to keep the S-meter below S9, while tuning the 
>PRESELECTOR."
>
>Is it "normal" to then be able to peak up the received signal using the 
>PRESELECTOR control after this tuning procedure?  I don't recall that 
>being the case in the past, but I can't honestly say that I've ever 
>checked it.  I follow the prescribed tuning procedure, and go.  For some 
>reason today, I adjusted the preselector some time after tuning thinking 
>the received signals were kind of low, and discovered that I could peak 
>them up, but lost about 1/4 to 1/3 of the output indication.
>
>Has anyone else observed this on their SR-150, or does the collective 
>brain trust have any thoughts?
>
>Thanks... and Happy New Year (or is that Hallicrafter's New Year?)
>
>73,
>
>John
>
>N0GII
>
>Denver, CO