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Re: New V5 with poor carrier suppression.
IMHO, THE NAT54S ARE INTERALLY matched. As a strip, same batch the second bat54s also has similar characteristics.? Can we get such balance with 4 discrete diodes, it is a long exercise to match etc On Fri, 8 Mar 2019, 8:19 am Tom, wb6b <wb6b@... wrote: Hi, |
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Re: The Iambic Mouse
I am using the mouse as a (ceramic) microphone for my Drake (the capsule fits perfectly in the place of the ball). Indeed I could use the two now unused buttons for a cw key as you have done hihi :) Might the squeeze function work with such a thing? Il 08/mar/2019 07:31, "Curt via Groups.Io" <wb8yyy=[email protected]> ha scritto: Dave |
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Maximum and minimum voltages for uBitX V5?
I'm building my uBitX v5 and have a couple of questions about power supply voltage.
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First, what are the minimum and maximum supply voltages that the uBitX is happy with? ?I may be powering the radio with a 12AH AGM battery that's kept charged by a solar panel. ?I'll probably set low voltage cutoff for the solar controller at 11.8 or 11.9 volts under load (I've seen that listed as 2 amps when transmitting). ?The float voltage will be 13.6 to 13.8 and there might be monthly excursions of 14.2 to 14.4. ?Some specific longer life AGM batteries are spec'ed to have a regular duration equalization charge - DataSafe 12HX330FR, for example - and I see no harm in occasionally taking any AGM battery to its maximum rated voltage (cyclic versus float).
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If the uBitX isn't happy with that range (the LM386 could be either a 12 or 18 volt chip as the schematic just has "LM386"), I can control the voltage delivered to the receive section with an XL6009 buck/boost converter (maximum input is 3 amps). ?The XL6009 can hold the voltage to 12.0 volts or whatever makes the radio happy ;-)
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Second, what's the maximum safe voltage for the PA? ?I could use 2 XL6009's, with one set for the receiver and the other set to the PA's maximum safe voltage to squeeze a few more watts out of it. ?I plan to have a fan running on +5 for RX and +12 for TX so there's some degree of cooling between transmissions.
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I've not been active on HF for a long time but did have some articles published back when I had antenna space. ?I'm supposed to be talking with a tree guy this week and I may soon have antenna space again ;-)
Published articles: "Gilding the Lily", 73 Magazine, October 1980
"Converting the Sears 40 Channel SSB CB Rig to 10 Meters", Cover Article, CQ Magazine, November 1980
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John
WB4HLZ
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Re: The Iambic Mouse
Dave
Nice to see this idea revived as I know I saw it decades ago for portable operation. Not everyone is doing 20 or 30 wpm and that is okay. A bunch of us also do mechanical keying in straight key century club. The nice organization is quite a hoot. Some even use a sideways key called a cootie, many handmade. Enjoy your radio. Curt |
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Re: The Iambic Mouse
(*chuckle*) This is the coolest thing I've seen all day! I'll admit I use a capacitive Touch Keyer with two horizontal paddles that I alternately touch with my index and ring finger to send.? That's not very different from what you've got there! The world is full of discarded mice.? Very cool use for one! Disclaimer: I'm a slow code guy so things that would drive a 20+ wpm dude nuts I might not notice.?? |
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Re: New V5 with poor carrier suppression.
Adding discrete diodes and a pot for the modulator to better suppress the carrier has been discussed here.
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I haven't heard of anybody who has done this and decided it was worth the trouble. Being an unshielded rig there is plenty of 12mhz energy from CLK0 flying about,? will likely still get significant carrier even with a perfectly balanced modulator. The compact board layout places the modulator moderately close to the 12mhz IF. > The mixer connected to CLK #2 could, also, cause an increased carrier if it was not in balance. > As the on-purpose unbalancing of it to produce CW signals demonstrates No. When transmitting CW, the firmware shuts down CLK0 and CLK1, sets CLK2 to the transmit frequency When receiving CW or SSB, and when transmitting SSB (all other cases), CLK2 operates at DialFreq+45mhz. So when transmitting SSB at 14mhz, the mixer at D1,D2 mixes 45mhz IF energy with a CLK2 of 45+14=59mhz to give a 59-45=14mhz product that goes on through the 30mhz LPF at L1,2,3,4 to the power amp. Any CLK2 "carrier" leakage there is easily stripped out by the 30mhz LPF. Also easily stripped out by the LPF? is the sum (at 45mhz + 59mhz) and the 45mhz IF energy. Jerry, KE7ER On Thu, Mar 7, 2019 at 06:49 PM, Tom, wb6b wrote:
In theory shouldn't the mixer attached to CLK #0 be balanced and suppress the carrier? In that case the filters only need to suppress the unwanted sideband, not the carrier. |
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Re: New V5 with poor carrier suppression.
Hi,
In theory shouldn't the mixer attached to CLK #0 be balanced and suppress the carrier? In that case the filters only need to suppress the unwanted sideband, not the carrier. The matched mixer diodes are supposed to be matched well enough to not require a balance adjustment control pot. But has anyone tried adding a manual balance adjustment to these radios. The mixer connected to CLK #2 could, also, cause an increased carrier if it was not in balance. As the on-purpose unbalancing of it to produce CW signals demonstrates. Maybe a mixer diode in your radio is out of spec.? Tom, wb6b |
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Re: cannot trust any version or any mod.
Jack Purdum
Also check your local Junior College/Universities EE or physics departments. Even some high schools have SA these days. Phone companies and cable TV companies may also have equipment. Jack, W8TEE
On Thursday, March 7, 2019, 7:22:39 PM EST, Laurence Oberman <oberman.l@...> wrote:
Mike Where are you located. I am sure there is a school in the area or a ham club that could help with test gear. Any Spectrum Analyser test tool. Even an sdr with a down converter and proper attenuation woul show the spurs. I am in Massachusetts and happy to try help you. Regards Laurence On Thu, Mar 7, 2019, 5:21 PM Michael Mitchell <mitchellmichaelh@...> wrote:
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Re: AGC Pre-Oders are in and built!
Ben, The board should work on a V5 Board. Where we tap for attenuation of loud signals, and where we draw our bias to adjust signal level from is still equivalent between V4 and V5. The only thing currently untested is board fit. Neither N8DAH or my self have a V5 board as of writing. I actually have a test file for someone to print to do a fit test/pictures for us to ensure that its 100% compatible. If the board does not line up correctly some simple jumpers to rewire the ground and +12V lines are all that should be needed to make the circuit work in place!
-- Tim Keller - KE2GKB |
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Re: cannot trust any version or any mod.
Laurence Oberman
Curt Indeed agreed. My V4 is only marginally out of spec on 20m using CW tests. The V5 seemed OK on all bands on CW but at the moment is picking up a? lot more broadcast signals off the same antenna. Very strange. Almost like it's more sensitive than the V4. I put a nooelec filter in line with the antenna and that helped. Anybody else finding the V5 more sensitive ? Will finish all tests this weekend and share. Thanks Laurence KB1HKO On Thu, Mar 7, 2019, 8:15 PM Curt via Groups.Io <wb8yyy=[email protected]> wrote: Michael |
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Re: cannot trust any version or any mod.
Michael
I anticipate that a reliable cure for spurious will emerge soon for v3 and v4, and may apply for v5. Its understood that most of us don't possess a spectrum analyzer. My local club is building 23 ubitx v4 units, and we are correcting spurious. I just got hack in town so I need to find the latest info. I hope you and others hold onto the ubitx to continue with the cool rig. My untreated rig is compliant before mods on several bands. My data is posted here, a summary table. Curt |
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Re: Installing Nextion Screen
...and don't forget to remove the microSD card after you've loaded the new firmware like I did, otherwise it won't work :) 73 de Mike
On Thursday, March 7, 2019, 5:23:38 p.m. EST, Brutus Laurentius <markhamfarm14@...> wrote:
This video demonstrates the process step by step. I had to pause the video and look closely to see where to connect the wires. |
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Re: cannot trust any version or any mod.
Laurence Oberman
Mike Where are you located. I am sure there is a school in the area or a ham club that could help with test gear. Any Spectrum Analyser test tool. Even an sdr with a down converter and proper attenuation woul show the spurs. I am in Massachusetts and happy to try help you. Regards Laurence On Thu, Mar 7, 2019, 5:21 PM Michael Mitchell <mitchellmichaelh@...> wrote:
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Re: cannot trust any version or any mod.
Michael Mitchell
¿ªÔÆÌåÓýI have to admit I do talk to it when I am working on it. But I always finish ,or at least as much as possible, finish what I start. Not having any real RF test gear I wont know if I am ¡°legal¡± or not. All my additions will connect to the radio after its working . I just mounted the parts and switches. Actually none need any mods to the radio except for the display. Thanks for the encouragement. ? Sent from for Windows 10 ? From: Laurence Oberman
Sent: Thursday, March 7, 2019 1:49 PM To: [email protected] Subject: Re: [BITX20] cannot trust any version or any mod. ? Mike I think some frustration indeed but I trust you will indeed get this unit working to your expectation and within FCC specs. What I would suggest is you work on that with as few additions as possible to the board, other than the needed mods. ? For me to be honest its part of the fun of this radio. ? I am an Electrical Engineer who went into Embedded software/hardware mostly digital very young and what this has done is force me once again to involve myself in RF electronics and its great. ? Sincerely Laurence KB1HKO ? On Thu, Mar 7, 2019 at 9:28 AM Michael Mitchell <mitchellmichaelh@...> wrote: >? > In the 70's I was a radio tech (marine and business ) I was an electronics teacher. What I am trying to say is I am perfectly able to get the radio working which is why I am not selling it until I do. What I am saying is even with all the band aids the radio was misrepresented and it seems new problems pop up every week.Therefor I cannot trust this radio. > At the moment I have $280 plus? invested.. If I sell it it will be an Ebay auction. If I dont sell it will sit on a shelf . >? > On Thu, Mar 7, 2019 at 9:17 AM Jim Myers <kd7eir@...> wrote: >>? >> Avoid the self-induced stress and tell us a price. Most of us are more than capable of making this radio perfectly legal and reliable. >? >? >? > -- > WM4MM > ? ? ? |
VE3MIC