Here is a power resistor I used in another dummy load. These could be an alternative if the ones specified for this project are hard to find. I used two on a heatsink. Possibility in oil the wattage these can handle would be increased. The small heatsinks attached, while in the oil would likely help.? Tom, wb6b 
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On Sat, Oct 27, 2018, 1:12 PM Frank Dinger , EI7KS < ei7ks.frank@...> wrote: Chinese on-line retailers sell electrets with external amplifier on a 15x20mm board complete with separate 5 pin header.? This unit seem to be very effective for BITX radios.? Past week? I received 2 pcs .
Frank? ,? EI7KS
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Re: SolderSmoke Podcast #207 uBITX 15 Mtrs, 60 mtrs, homebrew, antennas, Cubesats
Raj, what are the spurs like when running finals at higher voltages. 24v has been suggested.?
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Better yet, repeatedly do both steps until no further adjustment is needed.
I have no idea how the two different adjustments might affect each other with the firmware you are using.
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On Mon, Oct 29, 2018 at 09:17 AM, Jerry Gaffke wrote:
I suggest you set the BFO first, then calibrate the rig to be on the correct frequency.
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I don't know what firmware you are using or what instructions you are following. Tuning for zero-beat makes sense to me when calibrating the si5351 reference oscillator so the rig is on the correct frequency. But tuning for zero-beat does not make sense when setting the BFO offset with respect to the 12mhz filter. I don't think many firmware releases calibrate using algorithm of post?? ?/g/BITX20/message/54501or tune the rig following the algorithm of post?? /g/BITX20/message/44278That being the case, there may be weird dependencies between calibrating and setting the BFO, I suggest you set the BFO first, then calibrate the rig to be on the correct frequency. To set the BFO, I suggest you tune in an amateur SSB station, then set the BFO for best received audio. Ideally, find a station where the operator's voice is similar to your own (low, medium, or high pitched). When transmitting, the filter will be doing the same thing to your voice as rig does when receiving. Jerry?
On Mon, Oct 29, 2018 at 08:55 AM, Matthias Zwoch wrote:
Surely the BFO must be corrected. But how? I followed the instructions, got a AM station with known frequency and set BFO to zero beat.??
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After relay change my uBitx 4.3 is now capable for legal CW QSOs. So I did the next step and changed L5,L7 and L1 to 680 / 330 nH.
The first test on SSB via dummyload and 20db extra attenuation direct in the antenna of my good old SDR-IQ shows a rather clean signal in the RF spectrum at 10kHz width - but looking like AM and not like LSB on 3.6 MHz. Test with other stations confirmed that. The carrier is still present and the USB sideband is only 6dB down compared with LSB.
Surely the BFO must be corrected. But how? I followed the instructions, got a AM station with known frequency and set BFO to zero beat. Was then happy, to have a clean reception of all SSB stations on the QRGs where they were spotted.
73 Matthias, DD7NT
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Re: Sunil Lakhani's AGC board connections to uBITX
#ubitx
Merci, but no - what I am looking for is NOT in this .rar.
Jim
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Re: uBitX CW Sidetone Volume
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Re: uBitX CW Sidetone Volume
Raj, I will try this.
Bill... tried that, but when keying the transmitter, I still hear the bumping of Raduino... even if the CW TONE line is grounded.
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Re: Sunil Lakhani's AGC board connections to uBITX
#ubitx
Hello
Voici le fichier .rar
73 QRO F1BFU - Fr
Le?lun. 29 oct. 2018 ¨¤?14:38, Jim Sheldon < w0eb@...> a ¨¦crit?: Thanks Art, I already have that file and the actual schematic with connections shown is NOT in that .rar.? There was another one that got posted somewhere that actually had the connections for IF-1 and IF-2 shown on the AGC schematic but I need to know where those points actually are on a uBITX V4 board.? That's what I cant seem to find.
Jim
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Re: Sunil Lakhani's AGC board connections to uBITX
#ubitx
Thanks Art, I already have that file and the actual schematic with connections shown is NOT in that .rar.? There was another one that got posted somewhere that actually had the connections for IF-1 and IF-2 shown on the AGC schematic but I need to know where those points actually are on a uBITX V4 board.? That's what I cant seem to find.
Jim
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Re: Sunil Lakhani's AGC board connections to uBITX
#ubitx
That's not the AGC board, that's the front panel board to one of Sunil's cases.? The AGC board is a separate kit from them.
Jim
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Re: Sunil Lakhani's AGC board connections to uBITX
#ubitx
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On Oct 29, 2018, at 8:09 AM, Jim Sheldon < w0eb@...> wrote: Anyone have the schematic that shows how to connect Sunil Lakhani's AGC board kit to the uBITX?? I found a diagram that had all the connections once, and like a dummy forgot to print or save it.? Now, it seems to have disappeared.? It is not in the .rar archive file available on the website.
Any help would be greatly appreciated.? Sunil, if you read this please email me directly w0eb [at] cox dot net.
Thanks,
Jim Sheldon, W0EB
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Sunil Lakhani's AGC board connections to uBITX
#ubitx
Anyone have the schematic that shows how to connect Sunil Lakhani's AGC board kit to the uBITX?? I found a diagram that had all the connections once, and like a dummy forgot to print or save it.? Now, it seems to have disappeared.? It is not in the .rar archive file available on the www.amateurradiokits.in website.
Any help would be greatly appreciated.? Sunil, if you read this please email me directly w0eb [at] cox dot net.
Thanks,
Jim Sheldon, W0EB
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Re: uBitX CW Sidetone Volume
Hi,
I installed a small pot (10k) in series with the line into the audio channel from the Raduino. The trace I broke is on the top of uBitx mother board to the right of the Raduino socket (looking at the board from the front). I cut the trace with a hobby knife, scraped the green paint off, and soldered the center and one end of the pot to those leads. The sidetone volume can then be adjusted and mine is down with the level of incoming signals. Make sure the pot (and the cut trace) is far enough to the right to clear the Raduino when it is plugged in.
73,
Bill KU8H
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On 10/29/2018 05:51 AM, Marko Pavlicevic wrote: Even after replacing R253 with higher value, CW TONE is still loud.
If I remove R253, I can hear CW TONE in headphones!
Is there a way to implement CW TONE volume control in RADUINO?
--
bark less - wag more
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Re: uBitX CW Sidetone Volume
Try a 10K or 1K preset (center and one end) parallel with C252,
this should work with 10K but if not try a 1K preset.
Raj
At 29-10-18, you wrote:
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Even after replacing R253 with
higher value, CW TONE is still loud.
If I remove R253, I can hear CW TONE in headphones!
Is there a way to implement CW TONE volume control in RADUINO?
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Re: uBitX CW Sidetone Volume
Even after replacing R253 with higher value, CW TONE is still loud.
If I remove R253, I can hear CW TONE in headphones!
Is there a way to implement CW TONE volume control in RADUINO?
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Re: SolderSmoke Podcast #207 uBITX 15 Mtrs, 60 mtrs, homebrew, antennas, Cubesats
Curt,
The relays mod work very well. Change only KT 1/2/3 . The filter mod looses power so skip and reduce your drive
and that will keep the spurs down.
Raj
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At 29-10-18, you wrote: Made my first ubitx contacts this weekend - wow. It does CW nicely with straight key, with reception via NESCAF audio filter. did some SSB in CQWW - worked 23 or more countries. transmit audio seems to be effective, so maybe this rig doesn't need a speech processor after all. doing a group build - 23 total rigs. some have been measured for spurious - and clearly are not in compliance. we will be modifying each one with added relays and a 45 MHz filter stage - this fix does bring them into compliance. This rig was so much fun to operate, I wasn't tempted by the other rigs in the shack as I just wanted to have a little operating fun. 73 Curt
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Re: SolderSmoke Podcast #207 uBITX 15 Mtrs, 60 mtrs, homebrew, antennas, Cubesats
Made my first ubitx contacts this weekend - wow.? It does CW nicely with straight key, with reception via NESCAF audio filter.? did some SSB in CQWW - worked 23 or more countries.? transmit audio seems to be effective, so maybe this rig doesn't need a speech processor after all.? doing a group build - 23 total rigs.? some have been measured for spurious - and clearly are not in compliance.? we will be modifying each one with added relays and a 45 MHz filter stage - this fix does bring them into compliance.? This rig was so much fun to operate, I wasn't tempted by the other rigs in the shack as I just wanted to have a little operating fun.? 73 Curt
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Michael Shreeve
Jim Sheldon
Raj vu2zap