The HW-8 is a 4 band QRP transceiver kit manufactured by Heathkit.  It is a CW only rig which covers portions of the 80, 40, 20 and 15 meter bands.   I picked up my HW-8 at a swapmeet for $75.  Not sure that it was all that good of a buy, but have seen units in worse shape going for about the same price. The owner told me that it was in working condition and while this was true, it did take some work to get it working well.  I noticed right off that on 40 meters the Rx was somewhat deaf, stations I could hear with my Drake receiver couldn't be heard at all on the HW-8.  Also the Tx output was lower than I thought it should be.  After more checking I decided that the 80, 40 and 15 meter sections could use work both on Tx and Rx.  My unit didn't come with the manual so getting my hands on one was the first order of business  As I subscribe to QRP-L, a listserve which deals with all aspects of low power amateur radio, I sent a message to the list asking for help in obtaining a copy.  I couldn't believe how many offers I received and it wasn't long before I had one in my hot little hands.   I had remembered reading some posts on QRP-L about the HW-8 so I searched through the archives and found two very good articles by Michael Czuhajewski, WA8MCQ, about some problems he had found with the toroid cores used in the output filters of the 80 and 40 meter sections.  Armed with the manual and these articles I started work on my HW-8.   Step one was to go through the tune up instructions.  While doing this I discovered that while I could adjust the caps in the output filters, I was not able to peak them on 80, 40 and 15.  This just didn't seem right so using the information from the articles I purchased new cores and wound new coils.  I started with the 40 meter section and installed the new coils wound with a few extra turns.  I would then see if I could peek the cap and if not, would remove the coils, remove a turn from each and give it another try.  I noticed that with each removed turn the signal on my scope would get larger and after a few turns had been removed I reached a point where the trim cap would tune through a peak.  I then tried it with my antenna and wow what a difference, it could hear!   From there I continued on to the 80 and 15 meter sections and repeated the process with similar results.  Michael in his articles states that the cores in the 80 and 40 meter sections are the ones that go bad and that he has not run into any problems with those used in the 20 and 15 meter circuits.  In my case I did replace the cores in the 15 meter filter and after adjusting the number of turns on them was able to tune the trimmer cap through a peak.  It could be that the cores were okay and just didn't have the correct number of turns on them.  What ever the case, things were working much better after the core replacement.     With that task completed I again aligned the rig and then put it on the air.  Wow, this thing works great!