[Heath] HP-23 power supplies - an idea and some questions.

[Guy Giacopuzzi]

While I basically agree with Glen's history and assessment of Heath 
pushing 6146's, I have an interesting observation;  I've /never/ changed 
a pair of 6146's, except to change one because it didn't match the 
other.  I have an ICOM, a Yaesu, a few Collins, and a Drake 4 and 7 line 
, in addition to  my Heathkits.  The Heathkits are by and far the most 
reliable radios I own.  While I built my 401/303 combo while in college, 
the others were mostly swap finds, and still, I find them more reliable 
than all of my others....

Guy,

WA6OQQ, another ham at Heath....


On 2/4/2018 6:02 PM, Glen Zook via Heath wrote:
> Methinks you mean 3 dB instead of 1 dB with an increase from 100-watts 
> to 200-watts.  However, even that increase will not be noted in most 
> situations.
>
>
>
> As far as why Heath increased the voltage:  A new power transformer 
> was used in the HP-23A that had dual primary windings for 120 VAC and 
> 240 VAC.  Since a new transformer was being used, Heath went ahead and 
> increased the secondary voltage as well to increase the power on the 
> HW-10X and SB-1XX slightly.  Of course, Heath was never conservative 
> on the power ratings of their transmitters.  Having the slightly 
> higher voltage did allow the equipment to come closer to the power 
> ratings. However, it has been my experience working on a lot of Heath 
> equipment that to make the power claimed by Heath involved pushing the 
> 6146 final amplifier tubes often to beyond their ratings.
>
>
>
> Remember, the original 6146 and 6146A / 8298 were rated at 90-watts 
> for Class "C" operation, 85-watts for AB-1 / AB-2 for SSB, and 
> 67.5-watts for AM (all input ratings).  Heath pushed the tubes very 
> hard for both SSB and AM operation.  Of course, back then, the 6146 
> was in production and very common.  Therefore, who worried if the 
> tubes did not last as long as possible!
>
>
> Glen, K9STH
>
> Website: http://k9sth.net
>
>
> ------------------------------------------------------------------------
> *From:* Kenneth G. Gordon <kgordon2006 at frontier.com>
> *To:* Heath at puck.nether.net
> *Sent:* Sunday, February 4, 2018 7:35 PM
> *Subject:* Re: [Heath] HP-23 power supplies - an idea and some questions.
>
>
> You are absolutely correct, of course.
>
> In fact, in order to increase the signal level at the receiver enough 
> to hear a difference, one
> must double the output power of the transmitter. 100 watts to 200 
> watts for 1 db difference
> at the receiver.
>
> 1 entire S unit (or 6 db, i.e. a power ratio of 4) increase at the 
> receiver requires increasing
> transmitter output power from 100 watts to 400 watts. Then another S 
> unit above that
> requires 1600 watts. No thanks.
>
> I am not concerned about power output here: to my way of thinking, the 
> lower voltage simply
> "isn't right.".
>
> If it was not important, why did Heathkit change the AC voltage from 
> 268 to 282?
>
> Are there deleterious effects due to the lower voltage OTHER THAN 
> power output? I
> suspect so.
>
> Screen-grid issues come to mind.
>
> But none of the above concerns me.
>
> So, I still have not gotten an opinion or an answer to my question: is 
> it likely that the 410
> VDC across the 12.6 V winding of the added transformer is too much, or 
> is it acceptable?
>
> If no one knows, I believe I'll try it to see. Empirical evidence is 
> always good.
>
>
>
>
> _______________________________________________
> Heath mailing list
> Heath at puck.nether.net
> https://puck.nether.net/mailman/listinfo/heath

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