Hi,

well I finally hooked up my headphones output to FlDigi, and that confirmed my uBitx's BFO was off, giving an audio about 300Hz too high, which I corrected successflully via the setting BFO menu (I guess my problem was different with Vaughn's one).

I will try to make some phone contact to confirm the transmit audio is actually better now, as I don't have a dummy load to avoid overloading my test receiver.

Thank's again to all of you for you great help.

73s.


--
Laurent F5FIE.

Hello and thank you HAMs!!

This is the Ubitx of mine:

I'll assume you have a 40m dipole, with 20m traps halfway down each leg?
to prevent 20m energy from passing, so it is effectively a shorter dipole on 20m.

When operating on 20m, those traps are at the ends of the 20m dipole,
those ends have the same 3000 ohm impedance that we would have at?
the feedpoint of an end fed halfwave.? Actual impedance will vary depending on
trap construction, how close the wires are cut for resonance, nearby objects,?
height from ground, ...? ? But I'd expect this to be correct within a factor of two.

Power is Volts*Amps, or Volts*(Volts/Ohms).
25watts = Volts * Volts / 3000ohms,? ?so Volts = square_root(25 * 3000) = 274 Volts rms of 20m RF

Jerry, KE7ER

Thanks -- my goal with the uBITX was multiband ops with mini-effort and max coverage -- simplicity.? I wasn't smart enough to know what this means is you lose low SWR numbers. But then I wasn't smart enough to know that SWR below say 4 doesn't matter much on the receive end. So if you can get the big picture and understand the interaction of large numbers of errors, you realize the approach works great.? hahah

I'm sure the uBITX doesn't like high SWRs at some point, and i know there is no fold back or power reduction/protection circuity. But it seem to do just fine at 4 (or more...I'm just saying).? And yes I pay attention to the drive levels and stay within the envelope, but there is one drive setting for all bands.? I've seen WSJT-X config setting drive level per band, and I may play with that, but the uBITX takes care of itself with one drive setting for all the bands that I can use.?

Based on what I've read, the EFHW 80-10 antennas could do even better than my DIY 80-10 OCFD as they seem to have 30m out of the box. If I wanted to just by a good solution, I'd try these guys (or similar -- there are lots of vendors)



How can you beat?80/40/30/20/17/15/12/10m with no antenna tuner? Several guys in our local radio club have them, and they seem to work.

But given a easy, reliable, effective and efficient commercial solution like a EFHW-80-10, or a marginal self made mess, I will aways pick the mess.? My old boss used to say that when success is too easy, you should put obstacles in your way, just to make victory sweeter.?

V4 has lower than desirable audio gain. Add a single stage transistor before or after volume control.
It's fine with headphones.

Raj

I picked up a couple of SMA-BNC jumpers at the ham fest and was playing with it yesterday afternoon - here is a photo of a PWR scan of the broadcast FM band using an HT whip as an antenna - a few strong local stations show up
73,
Mike N2HTT

Hi Junior,

Not sure exactly what you did.? I have the same symptoms.? I can hear signals provided the antenna tuner is spot on but there should be substantially more audio.? Reading your note I am not sure exactly what you did to fix it.? Any clarification will be appreciated.?? Thanks Jeff

You mentioned "on Dummy Load only 10-11V", is that your power supply voltage when transmitting? The power output is very dependent on the voltage to the PA line, and if your power supply sags to 10-11 volts when transmitting then you will only get maybe 60% of normal power. Similarly, if you increase the voltage on the PA line youcan get more than "spec" power. It is a good idea to keep the main board voltage at 12v or less to avoid overheating the voltage regulators, but that is why there is a separate line to the final amplifier.

=VIc=

V4: One you do the spur mods these should reduce or go away!

Raj

OM

how is your output power on CW?? take power readings on CW even if you don't use this mode.? this will tell us how the PA etc are working.?

some experience weak audio drive that hampers SSB transmit power - a few in our club build.? I am fortunate that using a surplus speaker microphone I had works swell, but others are not so happy.? some are adding a preamp or even a speech processor IC to their audio chain.? I think you need some patient experimenting, after affirming CW power is okay.

if you have a different microphone to try - I would.? also consider building an audio oscillator as a test source.?

73 Curt

Congrats on turning it loose Don, those are some really nice results.? I'm envious of your antenna doing so well without a tuner.? I hadn't noticed those pie charts before, but yes 30m is a pretty good band these days, for small bandwidth work at least.??

Thanks exactly what I looking for......?

开云体育

Good idea. It bugs me too when I power off the radio and the raduino is still on. It powers the radio too because when I have my pan adapter hooked up I can still receive signal, just a little weaker. It’s so weird.?

I need your Help, reaaly no Idea for this low, very low Power Output..

...if there is an way, an idea or something i could do it was not described in any post till now or i read it not because i have read all post for this "low output power" issue what i can read in this forum, but i find difference things was write there and i look to make all i can test or put like these post was saying.. but nothing get right..

My problem is the output transmit power, get only 4W on 80m, 3-4W on 40m/20m and 1-2W on 15m/12m/10m and the messuare was take by Dummy Load and on Antenna the Value is the same so there not different and i have on 80m only 2 Qso and 40m only 1 Qso till now with many Antenna testet and other Band testet but not heared by other ham so same by test with websdr.com try to hear me, but there was nothing able to hear me..

so the test on RV2 and RV3 with fully clockwise: Rx only is 150mA, Tx PTT only without speaking is 380-400mA?
when set on RV2 and RV3 for each on 100mA, both together 200mA to the 380-400mA then i have 600mA PTT no speaking when the Bias setting up like it should sayed on hfsignals.com but now when Tx PTT now with a load Hallooo to the original Mic Cap, then the Current is 1Ampere but on Dummy Load only 10-11V and on Power Meter 3-4W and when set RV1 to max power at fully counter clockwise then 5W getting but overmodulation so i seg RV1 like half way like it was before.. now i have test the Q90 Transistor in no Battery,no Power up Ubitx for shortet Transistor but it does not give a short with dvm test or should i test it in other way?

The Q90 was my only idea to try a new on in TO-92 solder in but i don't know if i should do this or should test other things..

The R63 resistor i have read can be reduced to 22Ohm for more mic audio.. but that should not give the issue away because on CW my power output is the same low value at the bands and on 80m get 3-4W cw on 40m 2-3W and than it goes lower,too .. on higher bands like 20m,15m,10m it was 1-2W..

What can i do, WHAT SHOULD I DO? I want only the normaly power output like on hfsignals.com saying and the other user would have..i want it too..the normaly power..this is all i want, please..

The ubix, when it have at one day should have 10w on 80m and 7w on 40m and 20m, than i would be lucky as hell but in reality the ubitx should have this 10w on 80m and 7w on 40/20m or have i fucked something up in readi g this information all there was saying by the motly ubitx users they have this minimum 10w..?

I have good Receive, very good sounding and the only thing whit trouble is the power output is too low and thats all i would be have missing would say, when this issue gone cleaned up and the power output is on the right value with 10w my ubitx would be very best Qrp Transeiver for me and i'am lucky when dreaming of this many days outdoor transmitting i would love so much with this lovley little machine.. i have so much love to give kn this ubitx and i thought for many upgrades would be present when the transmitting output issue was done in right setting, i would upgrade things like agc, s-meter, cw-filter, battery-case, speech-ic, integrated qrp tuner with swr meter, these are the things i have here for waiting to build up and put in the ubitx..

So my project only make trouble in one point where i have no idea..