I found this site that might help you. Goto

http://www.inetport.com/~talen/sb104.html

This is a site on repairing the sb-104A.
Good luck. Greg.

Well I would start with the schematic and go for the 15 meter section. Im great with the SB and HW serier, but newer it's alot harder, maybe the band selector switch and trace that back to the circuits. You can post your question on my heathkit message board at

www.members3.Boardhost.com/heath32a

Maybe someone ther can help also. Greg.

I have 6 HF radio's, new and old. My favorite I use on a daily basis is a Heathkit 101. I prefer the tube radios. The 520 kenwood is a great rig and nothing built as solid as the old radios. My new kenwood just sits, anyone can buy a 1000, 2000 or 3000$ radio plug it in and work DX. Most DX I work can't believe im on a heathkit, get good reports also. Keep the 520, it's a part of radio history and a good old radio! 73....de...kf2tz..Greg.

Hello. My advice, replace the electrolytics with new. I do alot of heathkit repair and find the old electrolytic's are bad, ALL! Remember 20 or 30 years have gone by and they are dried out and way out of tolerance. New ones are alot smaller and not expensive at all. I just replaced caps in 2 HW-101's and rebuilt a HP-23 power supply. You will be glad you replaced the old ones. 73! Greg.

Hello. Go here to cross reference any tube.

http://hereford.ampr.org/cgi-bin/tube

Greg.

Hello. For a rig I would recomend a Kenwood. I have owned and used a good amount of radios and have owned all of the big 3 and I am strongly biased with kenwood. I picked up a TS-440 a couple months ago and couldn't be happier. Yaesu is also good, but there are more Kenwoods out there for your price range. You should be able to find alot of radios out there. Good luck! Greg.

Hello. In my opinion pick up a 15 meter module for the scout. 15 meters is always full of dx, not much rag chewing and has the CW novice part on the band for learning and picking up speed. 17 meters is too much rag chewing and almost no dx. 12 meters is very good but small like 17 and not open alot, like 6 meters! So try 15 meters, you wont be disapointed. Greg.

Hello. I would just buy or build an antenna for 2 meters. You can build one out of coat hangers and a 239 connector. I made one, used it for years. Could hit repeaters up to 75 miles away. Or buy a mag mount and make radials. Save the antron it will work good on 10 and 12 meters. Greg.

I've seen this problem before. In my case it was my tuner. Try the amp with a resonant antenna, no tuner and see what happens. Greg.

Hello. I have been using helicaly wound hamstick types for a few years and have always received good reports. As long as the swr is 1-1 you should get very good performace. It's funny when I work europe DX and they ask what is the set up im running mobile and I tell them a 4 foot hamstick and a HTX-100! I know a shortened antenna will not be as effecient as a dipole or other full legnth antenna, but as long as the swr is well under 1.5-1 you will do good. Greg.

I wouldn't even bother listening to that childrens band. Stick to 10 and 12 meters, you will find mature operators there.

Hello. The 6146W are the same as the 6146's just military grade. So use the W series they are better tubes. Stay away from the 6146 A's, they are only rated at 82 watts. The 6146 rated at 90 watts, 6146 B rated at 96 watts and the 6146 W at 100 watts. Greg.

Hello. I would stay with a straight key. I've been operating on CW since 93 and still use and prefer a straight key. I've used bugs and paddles, they are fun, but being new you will develop a good cadence useing a straight key. Have fun. Greg.

What frequencies are psk-31 on, on 2 meters. Greg.

Hmmm... You say a kenwood the worst sounding radio? You should try an Icom. I agree, the tube radios sound great. I'll always keep my Heathkit's.  Im looking for a kenwood now, for the receive quality. I can't stand my icom, it drives me crazy.73! Greg.