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THE AM BULLETIN BOARD => Technical Forum => Topic started by: ns7h on February 08, 2018, 06:34:43 PM



Title: Use of Heathkit HL 2200 (SB-220) on AM
Post by: ns7h on February 08, 2018, 06:34:43 PM
Any experiences out there using the SB 220 for AM driven by an Apache TX-1 or DX100 at a lower power setting such as 500 watts (input, not output for the SB-220) ~continuous duty?.  The use on RTTY at lower power is within its published applications but  is around 50% duty cycle.  Also the power increase from 100 watts plate modulation (output) to 200 -300 watts (output) from the SB-220) for noisy or QSB conditions on 75/40 AM is not a lot of gain.  I am looking for someone with the operating experience of this amplifier on AM to see if it is worth the effort (not too hard, but may be risky).  I have updated the HL-2200 with new power supply components and new 3-500s.  Output is 500-600 watts DC which should be normal for this amp at Class C operating conditions.

Thought I'd ask this community.  Thanks

Bob, NS7H


Title: Re: Use of Heathkit HL 2200 (SB-220) on AM
Post by: KD6VXI on February 08, 2018, 09:18:22 PM
I've run my sb220 at 250 watts of carrier for years.

125 pct positive peaks.  About 1250 pep.

Works fine.

Oil the fan every year.

--Shane
KD6VXI
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands