Adjusting the TX power of an Icom IC-FR4000 repeater

[Flameout]

The output power of my FR4000 is a little below specs of 10w/50w, at about 7.5 watts and 40 watts. Using the process in the attached photo, is it as simple as just increasing the numbers or is there much more to it? Would I do more harm than good by changing those settings? The other two photos are what it's currently set at. No idea if that is factory settings or someone else changed them over the years

 

 

 

 

[Radioguy7268]

What are you using to measure the power output?  Do you know it's an accurate measurement? Do you have a way to measure frequency stability and frequency center if you start changing power levels?

What do you wish to accomplish by raising the power, other than to reach the "maximum allowed"?  Raising the power on a smaller repeater generally increases the heat being generated, and reduces the duty cycle of the repeater. Many smaller repeaters were advertised as being 50% or even 100% duty cycle at high power, but in reality they don't last when you run them at full power for more than a few minutes at a time.  I won't get started on the overkill concept of using a 50 watt repeater to talk to 5 watt portables.

Sometimes less is more. I'd rather have 5 watts ERP at 100 ft. above average terrain than 50 watts at 10 ft.

Not exactly the answer you were asking for, but hopefully something to think about.

[SteveShannon]

@Flameout The actual effect of raising the power from 40 watts to 50 watts will make almost no difference in range.  It’s a waste of time.  You’re better off optimizing your antenna system including the feedline.  

[Guest]

In general terms:

Repeaters do not need "super power output" - their advantage is the setup: Technically superior and optimized transmitter setup and antenna (compared to HT).

Most repeaters do not have the problem of "being heard" (based on their setup and potential power output) - they struggle with "hearing" (a function of the users' choice of radios, settings, and locations).

Be aware that a repeater that transmits throughout the whole city with high power is useless if only its close neighbors can open up its receiver (use the repeater).

(I skip the discussion of rules and etiquette here)

@Radioguy7268 and @Sshannon are right on! 

1 hour ago, Radioguy7268 said:

Sometimes less is more. I'd rather have 5 watts ERP at 100 ft. above average terrain than 50 watts at 10 ft.

37 minutes ago, Sshannon said:

optimizing your antenna system including the feedline.  

Rule of thumb:

Use the power that is needed to be heard (by users) within an area that is close enough for most radios (those users) to be heard by the repeater.

If I can hear you (your repeater) but you (your repeater) cannot hear me, you become a nuisance with no utility (aka. interference )

 

Despite of the roadblocks and complication and questions and ... - I hope you are having fun fine tuning your machine !!! 

 

1 hour ago, Radioguy7268 said:

Not exactly the answer you were asking for, but hopefully something to think about.

 

[Flameout]

Thanks for the replies. I tested the power output with a Bird wattmeter. The repeater for now isn't in use, until I can figure out the CWID problem. Seems that some of these FR4000's will tx a cwid and some don't.

I'm not real concerned with increasing the output power. I was just more curious if it was really that easy or if it would harm the radio. I'm still playing around with it.  My antenna (DB404) for now is as high as I can possibly get it (about 40'), without getting a tower (and a divorce) and it's being fed with Andrew Heliax ldf4-50a

[Guest]

2 hours ago, Flameout said:

... without getting a tower (and a divorce) ...

That is a tough decision 

... a tower is really cool and it does improve the coverage !!! 

 

... between the tower and the divorce, it seems that keeping the current set-up will save you a lot of money 

 

[Guest]

2 hours ago, Flameout said:

... I was just more curious if it was really that easy ...

I once believed in easy (and unicorns)  and then I tried to front panel program a Baofeng  and a Wouxun 

[gortex2]

Out of the box into my 2600 service monitor I never saw more than 45 watts on high power. Remember specs is 10% +/- so if your showing 40 I think your good to go.