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Airplane1
Senior Member
Username: Airplane1
Post Number: 1064
Registered: 5-2004
| | Posted on Friday, August 15, 2008 - 7:08 am: | 
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I have an IC-7000, I did the TX expand and want to drive the amp with it on Am. Am on these radios are not the greatest but if the 7000 is turned down to about 25 watts or less and mic gain down to 50% or less it works great but not enough power to give it a punch. Turn the power up and the 7000 gets very hot on AM and the fan starts running fast which it did not do befor the conversion, but then I never tried AM with it befor the mod. I believe these rigs are made mostly for SSB ops.
Hope a TS-350 amp will work with the 7000.
sorry, did not mean to steal this thread.
AP |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 4371
Registered: 7-2004
| | Posted on Friday, August 15, 2008 - 6:13 pm: |
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the dx350 only requires at best 4 watts carrier to make 60 carrier(fully modulated, you'll see 250 PEP). i don't really think it's a good match at all for your ic7000, roger. for SSB, you should be able to get the ic7000 to make 'quality' 15 watts PEP, and see 250 PEP on the ts. but, that's not much more then a half S-unit in signal increase. is it worth the effort? THEORETICALLY, if you back the ic7000 down to 25 watts on AM, you SHOULD see 100 PEP-the rated output of the radio. i do not see the rated output on AM on any of my icoms-706mk2g, 735 & 746pro. and my 706 has been 'modded', more then just opening up the xmit range.
i assume you're trying to get a bit more power at the lowest cost, unfortunately, from experience, i can tell you that the way you are trying doesn't always give the results you hoped for! you really need about 400 PEP, or 100+ carrier on AM, to show anything substantial with 100 watt HF rigs. i like to play, but multi-thousands on a matching icom solid state amp is OUT OF THE QUESTION! unfortunately rm italy's klv1000p is next to impossible to find, but i think it would have made a pretty good match. high drive, tubes, and seemingly relatively clean when not driven to excess. the next lineup that fits the bill is by ameritron. modern, current, easily repaired-easily modded-and not all that pricey if you go with a lower end amp. still, 800 watts PEP is attainable for $900 or less, new, and i've seen them for $600 used. and 100 watts carrier/400 watts PEP on AM is quite agreeable with their power supply.
my 746pro is not expanded, but i have used it on 29.000 & 50.400AM, with so-so results. my 735 & 706 are modded for 11m, and used on AM on 10 & 11 (& 6m on the 706). the 735 is touchy, but with tons of mic amplification it can sound somewhat 'punchy'. my 706 has had rcv & xmit power mods done to it, i see 130+ on 10m & almost 120 on 11m, whereas 'untouched', its output was about 60% of its rating. i use external fans on both, they do get hot on SSB without them. on AM, i barely get PEP that is double the carrier before the audio quality goes to heck. at that point, audio is acceptable, and yes it gets HOT fast. with the fans on, it is just fine.
you are 100% correct that these radios are made for SSB ops. painstakingly tweak for the best sounding AM audio you can get out of it-using both the radios' controls, as well as experimenting with different mics(i was not happy with the icom sm20, the heil icM seems to be best on the 706 & 746), then add an amplifier for AM. cheap just doesn't work/cut it, with a $1500 radio, though. |
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