Title: Bad PA job outside of amateur bands
Post by: SP3OSJ on 13. May 2018, 21:03:03
Title: Re:Bad PA job outside of amateur bands
Post by: DF8OE on 14. May 2018, 07:27:19
Hi Artur,
not a bug - its a feature. Power out level is reduced dramatically outsinde the amateur bands included 11m band. There is no country on our planet where you can legally use a homebrew rig for 11m working.
It is a safety feature so that nobody can xmit there by accident. And there is no reason for transmitting outside the bands with high power ::). Only for measurement purposes - a few mW is enough.
vy 73
Andreas |
Title: Re:Bad PA job outside of amateur bands
Post by: pa3met on 14. May 2018, 12:02:14
on the other hand, if you want to drive a transverter I could think of the use of such frequencies. Obviously extreme high levels shoudl not be useable
Somethink like 26.....30 MHz to cover 4 MHz in the 70 or 23cm band. Or maybe even 144.....148 MHz transverters,
For 11m... well I fully agree on that one. (including the other bands, like 45m, etc the pirates seem to use)
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Title: Re:Bad PA job outside of amateur bands
Post by: DB4PLE on 14. May 2018, 15:43:50
Hi,
for the transverter use case you are right, and this might be a use case which we could support at some point. I indicated that to Artur, SP3OSJ in a different there in this forum, where I also mentioned the low power rule outside amateur bands.
In order to have somewhat consistent power output and TX IQ across a larger freqency range, we would need to add more calibration points and some other stuff. So it is most likely not a simple `we turn that "stupid" limitation off` thing.
73
Danilo
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Title: Re:Bad PA job outside of amateur bands
Post by: DF8OE on 14. May 2018, 18:42:48
And for the 1000th time I write:
I do not think it is a very good idea to take mcHF for transverter use or put a big PA to it. Signal quality - especial on higher frequencies > 20MHz - is not good enough to do so.
EDIT:
Bandfilters are designed for HAM bands usage. Some "outside bands" are covered because of the bandwidth - but most are not. So you will be captured in mountain-like peaks and deep dampings. If you want ot use transverter you have to do more hardware modification:
- add two low level output/input which are connected directly behind TX mixer and before RX preamp input
- do filtering exactly to the used span externally
- reduce modulation level so that you will reach better signal quality
I think it would be better to use another rig for transverter purposes...
vy 73
Andreas |
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