Re: QSX 10W HF Linear PA kit
I am thinking of putting a dummy load on the unused portion of the heat sink. Mount a switch to select antenna or dummy load. -- Mike AI4NS
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Mike Short <ai4ns.mike@...>
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#61223
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Re: Cursed?
My recent ubitx arrived with lsb bfo way off. Possibly these boards are okay, don't rule out something simple. Do note eith no agc, when signals are weak one must crank up the audio gain. Curt
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Curt
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#61222
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Re: my uBitx Power
Ok got it.
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Joe Puma <kd2nfc@...>
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#61221
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Re: Ubitx with 4 nos of IRF510 in the final
This was done some years back by a Japanese ham on an amp using RD16HH mosfets.** . I have limited documentation on this matter.? His modication was to put? approx 8T ECW (you choose dia )? on a
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Timothy Fidler <engstr@...>
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#61220
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Ubitx with 4 nos of IRF510 in the final
Dear friends, Can I use two IRF in parallel in UBITX to increase output power? So total 4 IRF in the final? 73ees John T.P., VU2JON TTRRA 80, 6th lane, TT Road, Kuriachira PO Thrissur 680 006 Kerala
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John T P
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#61218
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Re: Harmonics and Relay Replacement
Gene, Here's a post from the old thread on the spur fix: ? ??/g/BITX20/message/60678 The entire thread is worth browsng. Raj found that replacing the toroids at L5 and L7 with 1210
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Jerry Gaffke
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#61217
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wanted: ND6T AGC kit
If anyone has an ND6T AGC kit they would like to sell, please contact me. Darryl K0GV
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Darryl Ponder
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#61216
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Re: Harmonics and Relay Replacement
HI Raj, Thanks for the info, I have the relays on order. Should I also change L5/7 at the same time? (Exactly what is the L5/7 Change?, Is it a value change or just convert to SMT?) Gene N2IJF
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Gene Nitschke <genenitschke@...>
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#61215
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Re: my uBitx Power
Okay on SSB without talking that was .80a I forgot to mention that my measurements was taking while pressing the CW key. Joe
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Joe Puma <kd2nfc@...>
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#61214
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Re: Cursed?
I really do appreciate all the help everyone is offering, really gives me hope that I can get this working. As to the RF probe that Arv posted, I knew I had seen it before. It's part of the build
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David Berkompas <david.berkompas@...>
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#61213
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Re: Cursed?
Given that the problem is on audio Rx and the BFO mixer seems to work for? Tx I would try to lash up a known good high Z audio amp eg LM358 set at gain of 50 or so? with an earpiece and try moving
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Timothy Fidler <engstr@...>
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#61212
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Re: my uBitx Power
I should have said you need to subtract the Tx idle current instead of the Rx idle current. Sent from an iPhone, don't ask whose.
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Clark Martin
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#61211
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Re: Cursed?
Arv, Thanks, I really appreciate the help. I'll have to find a club member who'll let me borrow their scope. I was eyeing a Rigol DS1054Z, but really can't justify the price for the limited times I'll
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David Berkompas <david.berkompas@...>
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#61210
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Re: my uBitx Power
You also need to subtract the Tx idle current. You can find this by keying up the mic with no audio input. This current is mainly the bias current in the finals but also the relays and some other
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Clark Martin
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#61209
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Re: my uBitx Power
Hi Joe, You could separate the brown wire that feeds the Drains of the finals and measure just that current. It will probably not be substantially different from the way you did it - subtracting the
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Bill Cromwell
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#61208
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Re: TDA2822 Replacement
The population is likely to continue for at least another generation.
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Leland Lannoye
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#61207
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Re: Cursed?
Dave AI6K Having two uBITX boards that both do not receive well is interesting. Normally one would be able to compare a working board with a non-working one. Don't know what test equipment you might
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Arv Evans
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#61206
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my uBitx Power
Hey guys, I will probably have a watt meter in the coming weeks but I still haven¡¯t measured my power out on the uBitx. So with a dummy load hooked up I took some power measurements with my DMM. I
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Joe Puma <kd2nfc@...>
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#61205
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Re: Cursed?
It amazes me the problems people are having. I have only put one of these together, but I had absolutely no trouble. Used it for many WINLINK contacts. Before that I had a bid ex 40 which I also got
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Gordon Gibby <ggibby@...>
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#61204
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Re: Cursed?
On my v4 boards, first one is latest CEC firmware (1.1), and 2nd board is stock firmware. I hooked up my 706MkIIG to a mag-mount 10m antenna, picked up WWV just fine. Nothing on uBitx's. Tuned in some
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David Berkompas <david.berkompas@...>
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#61203
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