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THE AM BULLETIN BOARD => Technical Forum => Topic started by: k6hsg on March 28, 2012, 08:24:47 PM



Title: Icom 7600 Driving a Hercules 2??
Post by: k6hsg on March 28, 2012, 08:24:47 PM
I have an Icom 7600 which seems to be working well on AM with 30 watts carrier and I am thinking about using my
Ten-Tec Hercules 2 solid state 500 watt amplifier with it.  I would reduce the drive to get 100 watts carrier out of the Hercules which should give me around 400 watts peak?
Has anyone on the list done this and what do you all think?
Am I asking for trouble?
I am working slowly on a 2 813 rig from the 50's that I bought on ebay but it may end up in the estate sale before I get it running.

73, John


Title: Re: Icom 7600 riving a Hercules 2??
Post by: w4bfs on March 28, 2012, 10:10:47 PM
I have run an Icom 765 to a metron 1000b amp .... the drive requirement varies with frequency (8W drive on 80 m --> 200W carrier, etc)

you may need the alc - voltage to be adjustable with the simple external V divider ckt to properly control the rig and keep audio clean


Title: Re: Icom 7600 Driving a Hercules 2??
Post by: Pete, WA2CWA on March 28, 2012, 10:23:05 PM
On AM, I wouldn't connect any ALC line between the 7600 and the amp. You don't need it. Monitor your RF amp output with a scope. That's all you need running AM. For even better AM transmit "quality", especially if you use any type of outboard audio processing, use the direct modulation input on the ACC jack on the rear of the 7600.


Title: Re: Icom 7600 Driving a Hercules 2??
Post by: ke7trp on March 29, 2012, 12:47:14 PM
You wont get a clean true AM signal unless you build the external ALC box and hook it to the icom.  Then, You can turn the 7600's power up and then adjust the ALC knob to set your carrier.  You can then get a fully modulated signal.  The Device is cheap and easy to build. 

I posted here about the external alc box

http://amfone.net/Amforum/index.php?topic=25323.0

To give you an idea of the difference.  I recently ran my Icom in the AM mode on the 15 meter band to W0VMC. I used a commander 2500E amplifier. Carrier was 200 and the most I could get was about 50% mod. I saw peaks of 450 or so on the Power master.  With the box switched on and the same 200 watt carrier, PEP was now 1000.  I had to back the audio down to get the scope right at 100%. 

C
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