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Reviews For: Heathkit SB-220/SB-221

Category: Amplifiers: RF Power - HF & HF+6M

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Review Summary For : Heathkit SB-220/SB-221
Reviews: 76MSRP: 350.00 - 550.00
Description:
a 2kw pep input amp uses 2 3-500Zs
Product is not in production
More Info: http://www.vcnet.com/measures/
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
15765
N8MUS Rating: 2014-12-14
Original owner K8UA Time Owned: more than 12 months.
I am proud 2nd owner of a beautiful SB-220 originally meticulously assembled by Norm Mendendorp K8UA. Norm is now SK and I wanted post this review of his amp.

I purchased this back in 2006 from Norm, he had not used it in some years. Still is was clean inside and out and looked like new. I did the usual start up procedure for an amp not used in a long time. Everything was working and output was at spec. Interior build quality was amazing. It looks factory built. Norm was an electrical engineer and his workmanship is outstanding.

Since the amp worked so well I saw no need to add mods to deviate from what Heath kit originally designed. Then the high voltage started to drop. So purchased new caps, bleeder resistors, rebuilt the filter board, and installed the soft key kit.

Amp is back to full output, I did not buy the expensive caps but caps rated equal to or better and by purchasing the board rebuild parts verses replacing it I saved on that too. (I read all the information I could find first. Both from Harbach as well as Rick Measures. Ended up deciding mostly toward what Rick suggested.)

Though I did not originally assemble the kit it is neat to have a part in keeping this big green machine up and operating as well as making the few small improvements. It makes getting those great reports somehow more satisfying.

I find the layout well done, easy to work on and easy to maintain. Support is available as well as parts are easy to obtain. Lots and lots of information out there on the internet too.

Highly recommend if you can find a decent example to start with.

73

Jon
VA3AQB Rating: 2014-12-04
Great Amp Time Owned: 0 to 3 months.
I have a HL2200 which is the newer version of the SB221 but has the 10m MOD done.
I picked up a SB220 for $400 Canadian dollars and was advertised as tubes being old.
Well got it home opened it up and was very dirty inside. I spent a better part of a day cleaning it all up, everything was original inside.
I decided a update was in order, MODS done:

Harbach soft start
Harbach metering board
Harbach soft start
Grounded the grids
Harpen type Nichrone parasitic suppressors.
New Fan from Harbach

I decide I would add 6:1 reduction drives on the load and tune capacitors with pointers like the newer amplifiers. Basically when I set the preset values on a band 99% of the time it is spot on on the lower bands 10m & 12m about 70% of the time, just a little fine tuning which is now very easy with the 6:1 reduction drives.
I have the orignal Eimac tubes in both amps.
SB220 output on 110volts dedicated line 10awg less than 20foot wire run into a dummy load.

Key down:

40m, 1400watts
20m, 1350watts
17m, 1200watts
15m, 1200watts
12m, 1100watts
10m, 1000watts

never did on 80m but assuming the same as 40m.

Output is keeping plate around 600 ~ 650ma and grid around 200~250ma in SSB mode at about 70 ~ 85 watts input. This was just the test after all the mods I do not like to tune on key down anymore than 1KW as scared of burning out the band switch.

The original fan was noisy compared to my HL2200 it had a wobble so some vibration, I replaced it with the Harbach fan but still nosier than the HL2200. The new harbach fan is rated higher then original, faster and higher CFM. I decided to put a 50watt 33ohm resister in line for the fan just to slow down a little and reduce noise and now works like a charm and still a higher rated CFM than original.
I tend to use the HL2200 a little more but the SB220 is my pride and joy.
Future MODS: new caps for both amps from Harbach
If you get the chance to pick one up, go for it you will not be disappointed.
There is a lot of spare and replacment parts still around and a wealth of information on the Heathkit amps Yahoo group who can help you with any issues you may run into.

73


N0TES Rating: 2014-09-22
Work horse! Great for testing the limits Time Owned: more than 12 months.
I have this hooked up to a 220v 30a service outlet and purposely melt down antenna systems with it. It's a wonderful, even artistic, piece of equipment. It is fitting that it be used to create antenna systems by testing their limits. My amp gets to destroy and create new antenna systems for amateur radio operators. How cool is that? Now, imagine the abuse this amp has taken, for the last 7 years. It performs without a glitch even after all of what we use it for. So, I know what I am saying when I tell you, it'll serve you well.
N4WGY Rating: 2014-07-11
Awesome Big Green Tank Time Owned: 6 to 12 months.
I am the second owner of my SB-221 w/10 meter mod which was was incredibly well constructed and cared for by the original owner/silent key. Have been using it heavily for about 1 year at time of writing this review. I installed the Harbach Soft Start and Soft Key mods as well as the replacement high voltage capacitor board and diode board. Amplifier is currently wired for 120VAC power and still has the original 1982 vintage Eimac 3-500z tubes. The amp works incredibly well and reliably. Even with 120VAC supply it will easily make 600 to 800 watts with 80 watts drive. Amp is not designed for working WARC bands but it will tune 17 meters beautifully in the 15 meter position and 12m reasonably well in the 10m position. Have worked all over the world and USA with many an excellent signal report. The old tubes are beginning to get soft, especially on 10m and 15m, no fault of the amp there, just 32 year old well worn tubes. Only improvement I would have other than new tubes would be reduction drives for the Tune and Load capacitors to make fine tuning a bit easier.
KA4KOE Rating: 2014-05-05
Old warhorse Time Owned: 0 to 3 months.
Received a very nice SB220 in a trade. I installed the Harbach metering/rectifier and soft key boards. The amplifier has the original Eimac 3-500Z tubes. With 100W drive, the amp will just make 1200W. However, you should remember that the amp is not duty cycle rated for full power keydown. I typically run mine around 175W carrier when working AM. I drive my SB220 with a Flex 5K. The amp is extremely easy to tune, but gets a little dicey up on 10m, where thee power out-poot drops to about 800W.
PE1PMD Rating: 2013-11-25
Great amp! Time Owned: 6 to 12 months.
Years ago I sold my SB1000, still regret it every day. About half a year ago this SB220 was offered on a used products website in Belgium.
It was a 3 hour drive but worth it. The previous owner had plans to rebuild the amp but never got time for it.
All Harbach kits were with it and also the retrofit fan. A big smile when I drove back home...
First thing was the cabinet; it was painted black so got it cleaned and powercoated in the original color. The parasitic supressors are replaced by retrofits I found on Ebay. The coolers for 3-500z's are now hyper plate caps.
Rectifier board, softstart, capacitors etc. All the mods have been carried out and the amp performs like new. Recently I bought a brand new matched pair of RF-Parts 3-500ZG's but the original Eimac 3-500Z's are still in good condition. Last mod will be installing vacuum relays.
As you can see some time has been spend on this one... Was it worth it?
Absolutely, every minute! If you can find one at a reasonable price, buy it!
K1QN Rating: 2013-06-04
Immortal Classic Time Owned: N.A.
I built it in 1982. It never called for modification or repair. Totally functional, as advertised to this very day (2013).

----------------------
Earlier 5-star review posted by K1QN on 2006-11-01

Bought it and built it in 1981. Zero problems. The T/R voltage is a bit high, and I've been tempted, over the years, to put a remote solid state relay on it. (Use an old wall wart for power, put the "works" in a radio shack box.) It still looks and works great.
NN2X Rating: 2013-05-29
Works well Time Owned: 0 to 3 months.
My Main amplifier (QRO 2500DX), just failed, and had to send back to Factory, I recieved a SB 220 AMP, to hold me over, well to my surprise the old AMP works well..! The AMP generate PEP, 1200 Watts...(20 Meters), not bad..(Old tubes also)

Although not my QRO 2500DX, it does do the job...and can't beat the price, especially considering the watts out..!
K6BF Rating: 2012-05-02
Oldie but goodie Time Owned: 0 to 3 months.
I got this SB-220 from the original builder for about 350.00, I installed my NOS Eimacs from 1987 and was still making pretty good power! I have since re-capped it, added a glitch resistor to the B+ line, replaced the rectifier diodes, added step-start and re-lube the fan,Added QSK Vacuum Relay wow its very quite. It has been in daily use since acquiring without a hiccup, contesting for entire weekends, running rtty contests at 400-500 watts, phone and cw contests at over 1KW no problems. It is a very dependable piece of gear, and regardless of any future amp purchases, this one ain't for sale! For what I have invested, it's probably the best bargain in the shack!!
W1BR Rating: 2012-03-27
An Old Workhorse Time Owned: more than 12 months.
I've owned my SB-220 since the early 1980s. I bought it used, and only replaced the filter caps when I first received it. I'm still on the set of Eimac tubes that came with it. These amps are real workhorses, but of course they also date back to when the FCC rules stated 1kW CW input power limits. A modern amp using the same tubes will do more power, but it will also run a pair of 3-500Z tubes much harder to do so.

My amp wasn't very pretty to look at, and I doubt than anyone would have bought except to strip for parts, or perhaps for a 6-meter conversion.
After years of neglect and abuse, I decided to go through the amp with the intention of making it good as new. I added 160 meters, and also the WD7S TU-6A input board. These Harbach upgrades were also included: soft key, soft start, replacement meter board and also the filter capacitor bank. While I was at it, I added vacuum relays for full QSK keying, and a vernier dial drive for the plate tank tuning. A replacement backface panel is on order. The grids are now directly grounded, as suggested by W8JI on his webpages. I also replaced the original plate choke with the choke Ameritron uses on their amps. It was worth the work. The amp easily delivers 1kw CW on all bands, including WARC and 160 meters, with reasonable grid current and in the low power position. What a difference! I know a lot of hams feel that doing this much work to an old amp is foolish, but the amp now performs as good as any amp I could hope to own, at least within my budget!