[Hammarlund] SP-600 questions,many questions

[steve maus]

Greetings all,  After a year and a half of swl an a dx-398 I began to hunger for a more 
substantial radio and found one of these beauties at a local hamfest, a JX-1  ser.#4646,  
in good operating cond. "with 'almost' all the caps replaced."  I, of course love it, but I 
have a few questions.  On the audio output strip the 600 ohms is scratched out and 8 
ohms marked in. The radio sounds good, esp. strong signals, but the former owner didn't 
know what had been done, and I wonder, if the radio were still in the original 600 ohm 
config. would it be obvious to an ignorant newb like myself? Looking underneath, no 
additional transformer has been added between T-7 and the speaker terminals however  
T-7 has only 4 pins whereas every photo or schematic I can find shows 8.  And 
headphones. A pair of 600 ohm phones plugged into the front panel gives only a faint 
signal. I got a "600 to 4000 ohm headphone transformer"  from Fair Radio  and that 
maybe doubles the volume but it's still quiet and kind of washed out sounding. The 
previous owner thought the terminals marked "phono" on the back of the radio were for 
headphones but I see, cruising the online manuals this was for a phohograph or other 
audio input. Just for the heck of it I touched the headphone plug across those terminals 
and darned if there wasn't a good signal. Could that be the case if this was still functioning 
as an input?  Would it be bad form to attach a headphone jack here?   How about 
attaching it at the speaker terminals, perhaps with another volume control, and would the 
headphones provide an adequate load for the amp? And one more question. The 
frequency displayed by the dial matches that received pretty closely through the middle of 
the HF bands but is off a bit by the time I get to New  Zealand at 17.675Mc. or CHU at 
7.335 and off alot should I wander down to WWCR at 3.210.  Is this indicative of any 
particular weakness or need of any sort of tune up?    Thanking you in advance, Steve  
in Texas