[TenTec] Power supply for Hercules II

[Greg S]

Spend the $ on an AGM battery, and charge it in place. I ran my SGC-500 that way for 10+ years. I only turned the power supply on when operating, and it was an older Astron switcher, with the output voltage turned up. (As an aside, I ABUSED that power supply mercilessly. Still have it, still works perfectly....must be that TenTec sticker they put on it!)
 
The linked mod for improving connector supply current, or one similar is probably advisable, since those original connectors are far from new condition. Voltage drop IS your enemy.  
 
I am now the happy user of a TG electronics voltage booster.....great product.      
 
 
 
Other thoughts....AGM batteries have lower internal resistance, so hold voltage higher on peak instantaneous draws.....important as well: they ACCEPT recharge faster, as well. I was always going to try putting one of those multi-Farad capacitors the kids use on car stereo amps right at the terminals of my amp, but never tried it. They are fairly reasonable....might be worth experimentation.  
 
My experience, and random thoughts....hope something helpful in there.
 

 
Greg Schippers, KC8HXO  
 
 
 

 
 
>  
> On May 10, 2017 at 13:06,  <Katz Ajamas (mailto:ajamas.rn at gmail.com)>  wrote:
>  
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>  I am using a battery at present. It works well but but I do not charge 
> indoors and with an expectation of increased operating time, charging is 
> going to be a hassle. Also, once past 20% discharge, it's no better than 
> the SMPS I have. 
>
> The 2SC2879 transistors are supposed to run at 12.5V for best intermod 
> specs. The HP SMPS supply I have now barely makes 12.3V. There is a good 
> bit of drop in the stock Tentec cable and some more with the inner 
> connections.. The connector appears to be rated for the current. Bottom 
> line, the devices are running at about 11.6V for 500W output. 
>
> I'd like to find a matching Tentec supply for a reasonable (caps likely 
> need to be replaced) price. 
>
> Looking around at other options, there is a "Meanwell" brand SMPS at Mouser 
> and Arrow that makes 13.5V-16V adjustable, has voltage sense lines that can 
> be wired to the collectors, and can be turned on and off with a TTL signal. 
> It is class B EMI rated. 
>
> In trying to get a handle on the class B spec, I find a radio station on 
> 1.5MHz and has a 400uV/m contour at my location is S7. Alas, the class B 
> spec is for a conducted "limit" and does not make sense at 250uV as this 
> will be very sensitive to the impedance of the 'antenna'. Is this the 
> common mode PtoP that is acceptable at the power leads? In OR out? 
>
>
> The supply is $259 with free shipping from Arrow. Same price from Mouser 
> but plus shipping. $219 plus $30 shipping from HongKong seller. Mouser 
> looks like the best bet because they have a 30 day return policy. Unless, 
> someone who has used one of these can tell me about EMI and also about 
> whether it is reasonable to turn the supply and Hercules on during transmit 
> and off during receive. I'm not talking QSK rates. Just between exchanges. 
>
> What say? 
>
> 73, -Bob 
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> -- 
> -do not look into LASER with remaining eye! 
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