[CQ-Contest] Modify AL-1200 HV Power Supply by adding 2 capacitors & bleeder resistors

[w5wz at w5wz.com]

I believe it would; I have not studied the AL-82 schematic to confirm.
--Scott, W5WZ




On 2019-09-13 06:56, George Harlem wrote:
> Wouldn’t this modification also improve the AL-82?
> 
> George W1EBI
> 
> From George's iPhone
> 
> On Sep 12, 2019, at 7:59 PM, w5wz at w5wz.com wrote:
> 
>> Ray W2RE was with me in the Dayton flea market around 2010 or 2012
>> when I saw this AL-1200.  He told me he had a couple, and they were
>> good contesting amps.  So, I bought it.  Turns out, his call sign is
>> again associated with this amp as I've had to repair/modify its HV
>> power supply and sought info online.
>> 
>> WARNING – LETHAL VOLTAGES!!! DO NOT ATTEMPT WITHOUT PROPER SAFETY
>> PRECAUTIONS!!!  I’m not responsible for what you do with this
>> information!
>> 
>> The Ameritron AL-1200 has a 3,600v power supply. Its filter
>> capacitor bank of eight, 270mF 450vDC runs right at the limit of its
>> design (8 x 450 = 3600). A common modification is to add two
>> additional capacitors, along with the needed bleeder resistors, to
>> increase the filter bank capacity to 4,500v (10 x 450=4,500). Keep
>> in mind that the transformer still puts out 3,600v, so this
>> modification essentially allows the components in the filter bank to
>> have some overhead capacity.
>> 
>> W8JI and W7RY both offer a replacement PCB designed for 10
>> capacitors.
>> 
>> W1QJ described the way he modified an AL-1200 for W2RE here:
>> 
> https://forums.qrz.com/index.php?threads/al-1200-power-supply-project.369641/
>> 
>> I choose to adopt the W1QJ method, and show how I did in the W5WZ
>> blog.  This will also work in the AL-1500 equally well.
>> 
>> https://www.w5wz.com/2019/09/modify-al-1200-hv-power-supply/
>> 
>> --Scott, W5WZ
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