Hi all: 

 

I've been running a Heathkit SB-220 HF amplifier for the past 5 months and the overall output #s, aren't on par with a couple of other 220s that are in operation in my area. 

My Amp is bone stock and original tubes. I don't know if the other amps are because I don't know the operators personally., only one. 

The #s they claim are 100W in = 1KW CW, 100 in = 1800/2KW SSB.

I use an LDG Electronics TW-1 meter. 



Here's my amplifier tune up procedure with my antenna tuned to a 1 to 1 SWR. 

 

1. Set  the Exciter drive at 10W, CW, on desired band. 

2. Place the Amplifier in the CW/Tune position on same band. 

3. Key the exciter and amplifier, adjust the tune control to increase the pitch of my meter, about 10 seconds of key down, return to receive. 

4. Key the exciter and amplifier,  adjust the load control to increase the pitch of my meter further, about 10 seconds of key down, return to receive. 

Key the exciter and amplifier to get a reading: 10W in = 170 out. 

5. Place the amp in stand by and increase the exciter's drive to 100W. 

6. Key the exciter and amplifier, adjust the load control, increasing the pitch of my meter to its maximum, about 10 seconds of key down, return to receive.  

Key the exciter and amplifier to get a reading: 100W in = 1030 out. 

7. I switch the amp to SSB, leaving the exciter in CW, key the exciter and amp to take a reading, 

100W = 1237 out. 

As my meter requires a continuous carrier to function, this is why I leave my exciter in CW and switch the amp to SSB for the final reading. 

I reduce the drive to 75W, with the exciter in CW and amp in SSB, I see about 1KW out. 

LDG Electronics claim that there is about a 5 to 10 percent inaccuracy on the measurements. 

Should I be concerned about these figures, are they normal, should I consider replacing my power supply components and or tubes? 

 

Thanks & 73: 

 

Michael De VO1RYN