icom 7300 average power mod

[1iwilly]

Has anyone here performed the capacitor mod using a tantalum capacitor to increase the average power on SSB? The radio typically only operates at 30 to 40 watts. The mod is supposed to increase it. This modification was done by SP3RNZ. I'm trying to hear the pros and cons.

 

[sp5it]

7300 operates 90-100W even without the mod, but I know many people done that and still transmitting.
Mike

 

[AudioShockwav]

What kind of meter?
SSB needs a peak reading feature to show properly.

73
Jeff

 

[1iwilly]

What kind of meter?
SSB needs a peak reading feature to show properly.

73
Jeff

It does NOT increase the power output. That stays the same, only the average power is increased. Here is the article =https://sp3rnz.blogspot.com/2017/01/icom-ic-7300-ssb-power-mod.html

 

[Justme]

How is the signal on spectrum scope after doing that?, more stress for the P.A. as well, not worth it use amp if you need more power.
Good settings of compressor tone controls will do more for you.
My FTdx 10 shows 40 tto 50 watts on the meter on the Daiwa CN 801 in PEP mode 100 watts.
I' m heard on all 5 continents even without using the Acom 500 s amp.

 

[Moleculo]

I read the comments on the OP concerned about stressing the PA by doing this. I would be very surprised if a modest change to the ALC circuit to increase average power by a few watts would stress it, especially considering the same PA is capable of producing a full 100 watts on CW. The questions about adding to the overshoot problem are good questions - the 7300 (and other Icom rigs) are notorious for this.

Other manufacturers are now using other methods to achieve greater average power output on SSB. For example, Elecraft has added a CESSB algorithm to the K4 to achieve greater average power without adding distortion. Here's an article about that posted here: https://elecraft.com/blogs/elecraft-news/elecraft-k4-compression-with-cessb

 

[AudioShockwav]

CESSB

My best Homer Simpson drool face.......



73
Jeff

 

[1iwilly]

I found a video where, if you go into tech mode by using a shunt in the back of the radio, then press menu & function, then power; if you increase the RF power from 100 to 120, it increases the average power. Instead of seeing 50 watts average, now you will see 60 to 75 on average and 130 on PEP. With the cap mod, it increases the average to around 80 watts and PEP to 120 without increasing the RF power, still dead keying 100 watts. When doing it through the software, you have to increase the power to achieve about the same.

 

[Justme]

What is the interest of all these golden screwdriver mods?
The makers of he radio did design all components to last a long time using the radio as is, most of us here understand using a standard swr meter or the radio's internal meter is giving average power NOT P.E.P. power, use good decent P.E.P. meter...
99% of factory radios do deliver 100 watt P.E.P, i rather have a clean signal with 100 watts as a splatter box running 130 watts or overdriven modulation your fellow hams will thank you for that..
I have the Acom 500 S amp if i need more power from 160 to and 4 meter.
To get 1 S point more you need to increase power 4 x.... from 100 to 400 watts.

Modern radio's have enough tweaks on board with parametric equalizers and compressors too up average power to decent levels.
I do use the EQplus from Julius W2IHY for that, and carefull tweaking of the FT dx 10 internal equalizer and no compressor because the compressor/limiter of the EQplus is a tad better as the radio one.

Don't get fixated on meters swinging, care for a clean good signal.
99% of our contacts come from propagation not how loud we sound with over driven average power.
Improve your antenna system, good connectors good low loss coax, decent antenna, 48 years back when i was licensed the going story was 1000 dollar for a set up? spend 900 on your antenna system..

I hardly run my amplifier 100 watt i reach all 5 continents conditions applying.
Getting compliments of my audio unsollicitated, and clean signal as well.
I get more satisfaction of that as seeing a meter swing a bit more and have a crappy signal out...

But hey, it is your station you do what you want, i just see it from my perspective, here in the EU bands are mostly wall to wall full of hams so a clean signal is much appreciated here.
Reason why i don't do ESSB as well i pick bandwidth as conditions apply if that is 2400 to 3100 Hz wide.

 

[1iwilly]

I finally received a response from the guy. i ask=
Hello, i found your article for the ICOM 7300 to increase the average output
i would like to try this mod. But I have a question, will doing this cause splatter when using an amplifier?? His response is

From:QSL Manager OT 27 Grzegorz SP3RNZ
sp3rnz@wp.pl
To:
jvillafane@aol.com

Tue, Sep 9 at 12:52 PM

Good morning.

You should not worry about the splatter because we are just lenghtening ALC attacking time with this mod.
It has nothing to do with PA inside the radio or whatever.
Surplus of this mod is, You have to lower Mic gain, and lower compression a bit, just one two steps to keep it good with your voice.
Again, we are not changing anything in the service hidden menu like some "wise" guys doing, the problem in 7300 is that they programmed a very short ALC control time.
It's easy to prove that when you whistle into the mic, power is around 90-100W. It's because the single tone is not attenuated. Voice is a combination of high and low frequencies.
Thus, ALC is trying to limit the level. No idea what for. Users lifting MIC gain up to 8-9 and adding compression 5 and above.
THAT is causing distortion when ADC is overmodulated.

At least 50 were modded up to date, and nobody complained about any troubles.


Good luck!