A couple years back, I sold my amplifier at a hamfest… 3 years later, I got an email from the newest owner asking about it’s history… might as well post the history and some links and resources here for others!

In 1999-2004, I was a part of W0EEE, and very active.   They had an SB-220 that had been around for maaannnyyy years – it was so old, there were stories of Ward Silver, N0AX, fixing things with “bubble gum repairs” as a young man.  I grew accustomed to, and familiar with, that amp.  It had issues from time to time, including a little detonation due to parasitics damaging the tubes.   It went to Tom Hammond, N0SS (SK) a couple times for repairs.   The man was an absolute saint when it came to patience with us on it.

In 2004, I graduated and moved to St. Louis, but kept in contact with the folks in Rolla, as I was working for Boeing.

Dave, KF0XQ, sent a message about an estate sale while I was in my first apartment.  Among the items were the SB-221 that Dell Gossett (callsign escapes me) had.  The amp, as I acquired it, had a heavy duty switch installed in the front panel as a standby switch, and a 2 prong outlet in the back panel.  Furthermore, 10 meters was added, and someone with a lot better handwriting than me added a “10M” spot to the bandswitch.  Aside from that, I knew of no other modifications.

After the bad experience with an amplifier detonating at W0EEE, I immediately began procuring “things”…  Harbach modifications.  www.harbachelectronics.com

  • New power supply filter caps (protects the tubes, and the old caps took a beating as part of the design)
  • new meter protection circuitry (the W0EEE model had a mismatched set of meters because the old HK meters are unobtanium, so if they die, you replace them with something similar, but it will never be the same shape)
  • Soft key kit – isolates your transciever’s keying circuit form the high voltage the amplifier used (which was compatible with the old heathkit rigs of the day)
  • soft start kit – applies power to the amplifier’s power supply in 2 stages to limit inrush
  • parasitic suppressor kit (Harbach doesn’t seem to have these anymore – but some google searching should help. The original Harbach part number was PS-220 and i believe based on work by R. Measures, c. 1988 -article here: https://www.qsl.net/wa5bxo/ag6k/Oct88qst.html Mr. Measure’s site is still here: https://www.qsl.net/w/wa5bxo/ag6k/)

I moved to my first house in 2005(ish), and the amp came with.   I did not have 220V in the room for it, as I recall, but I did all the mods, except the parasitic kit.  I also replaced the 2 prong outlet with a 3 prong outlet I found at Gateway Electronics (SK) that was a darned close fit… and added the red flip-up cover to the standby switch.   It just felt GOOD to flip that cover up to bring the fire to the backyard antennas!!

In 2007, I moved to Cedar Rapids, Iowa.   One of the things I did was to build out a radio room in what the previous owners used as a workshop and laundry hanging room.  You bet I pulled a 220 line to the room for it.   I later moved the shack, and moved the 220 line in there, too… but i digress.

I met Rod Blocksome,K0DAS while I was up (here).   He was recommended by K2DP as an amplifier EXPERT – and he was apparently the brains and hands behind many of the amplifier projects and other weird operating activities at N0MA.   I pinged Rod and asked if he’d look over my amp.  He graciously accepted, and checked the whole thing over for proper and safe operation.  He removed the soft start kit as “I Don’t know what this junk is, but it’s not necessary”, and got the parasitic suppressor installed for me.   He is the one who took the band / power measurements and put them on the card.  

In 2013, I moved to St. Louis, and had the amplifier mounted in a centracom console, which required a custom plate (which should have been included with the amp, I think).  

A shout out to Novexcomm – when I set out to do the centracom project, I had the consoles, but I needed faceplates.   I filled out their online info request form at like 1:30 in the morning.   within 5 minutes, Bob at Novexcomm was CALLING my phone from california.   We worked out a deal with some shipping and engineering (the SB220 was a bit heavier and bigger than the typical motorola gear from that console).   I LOVED that setup.

One note- Around this time, I got tired of looking at the dodgy old PL-259s (I hate PL-259s, really… ), and I replaced them with type N connectors – which was a huge improvement in my opinion. I originally wanted a BNC on the input, but couldn’t find one to match the flange hole pattern in the amplifier chassis

In 2016, life moved on…     I dismantled and sold off the centracom racks.  When I finished my basement in 2017, I pulled 220V again to 2 places….   but in 2020, I left Boeing and moved back to Cedar Rapids.   When I saw the move coming, I decided to sell off the SB220, so it went to winterfest as part of a “major liquidation” effort.   I had plans to build up a solid state amp, and was even thinking about picking up pieces for said effort.   Never did get around to that… and I ended up finding a super deal on an Icom PW-1, which frees up a lot of operating desk space.  And with a move to Fort Worth in june, I won’t need something heating up the shack as much anymore!