80 Meters Harmonics Fix Proposal
I previously mentioned that I would try to reduce the harmonics by changing the output to 25 ohms and adding a step up transformer to go back to 50 ohms for the output. This would allow tripling the
By
Howard Fidel
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#58505
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Re: TIA amplifiers
An alternate improvement is replace Q10/11/12 with mmbt2369 or BFr106 as the 3904 is not impressive at 45mhz. Allison
By
ajparent1/kb1gmx
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#58504
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Re: UBITX TX level diagramme
Henning, There are errors in the diagram and the levels are really different than shown. Looked at your diagram and its assumptions are wrong.? If the final mixer can accept -1dbm without producing
By
ajparent1/kb1gmx
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#58503
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Re: UBITX TX level diagramme
Lawrence G., I tried a few things along that path.? made matters worse and that was also tried with external level 7 mixer and level 17 external mixers.? ?It was then a rock fell on me and I
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ajparent1/kb1gmx
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#58502
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Re: CW OPERATION
That¡¯s funny! Best little joke today!! Even a novice in my day knew that kind of stuff. Oh how times change !!
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Gordon Gibby <ggibby@...>
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#58501
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Re: UBITX TX level diagramme
MRM, The not so funny part Is I've been saying that for over two years and especially the last two months. The whole idea of minimally filter 3-30 mhz radio is wishful thinking.? When I first said
By
ajparent1/kb1gmx
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#58500
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Re: Arduino/Clock question/resolution
I solved the root cause, an open wire. But, now the Arduino does strange things, it locks up, sometimes I get very distorted CW xmit waveforms. The mystery continues.
By
Howard Fidel
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#58499
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Re: CW OPERATION
There is also the outstanding, yet related, issue with switching sidebands on CW (i.e. CWU to CWL or vice versa) with KD8CEC's code which I had? previously documented.? Try this on any commercial
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Michael VE3WMB
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#58498
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Re: CW OPERATION
Gordon. we have people with their extra that can't figure out how to connect the key to their radio (not just bitx radios, commercial too). How do you figure they're able to detect their band edges on
By
Vince Vielhaber <vev@...>
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#58497
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Re: raduino 1.27 upgrade
Hello Allard, I am a CW-only ham, so your 1.27.7 sketch made me love the BITX40. Today I tried to upload the 1.28 upgrade but, surprisingly, it does not sense the key and transmit CW any more.
By
Jep
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#58496
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Re: CW OPERATION
Gordon and all, His software is on our group website in the "Files" section. Jim, W0EB http://www.w0eb.com we do not use github
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Jim Sheldon
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#58495
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Re: CW OPERATION
Ron Where do I go to look for your group software? Now that I got my harmonic somewhat more under control, I¡¯m going to want to pick out good software modify it if needed and have it ready for our
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Gordon Gibby <ggibby@...>
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#58494
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Re: uBitx Unfiltered
Sort of¡ I added a second receiver to my uBITx on VFO B. It¡¯s great for DXing. I, like you, do like the uBITx receiver. You can even do some clever things with the audio (stereo channels one for
By
MadRadioModder
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#58493
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TIA amplifiers
Dear members you can check: 1. Add parallel to R12 C=470 pF: in my analiser I could see 3 dB gain rising on 30 MHz, 0805 smd resistor over R12; 2. Added two 100 Ohm? to collectotrs Q11 and Q12 (had
By
George
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#58492
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Re: uBitx Unfiltered
W.r.t the current discussions on ubitx transmitter woes ... the route forward that I chose was to order LPFs plus the relay board from QRP Labs. My thoughts were to use a 2nd Arduino Nano clone
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Michael VE3WMB
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#58490
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Re: K5BCQ uBITX Relay Switched LPF/BPF board
You can assign the filters to any LPF/BPF you want. Your list looks good to me, maybe combine the 12m/10m LPFs and make the 15m a BPF. 73 Kees K5BCQ
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Kees T
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#58489
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Re: K5BCQ uBITX Relay Switched LPF/BPF board
W0PWE Sep 2???#58462??( /g/BITX20/message/58462 ) Kees - With 6 filters is the plan as follows? LPF1 = 80M LPF2 = 40M and 30M LPF3 = 20M and 17M LPF4 = 15M LPF5 = 12M LPF6 = 10M
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Kees T
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#58488
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Re: K5BCQ uBITX Relay Switched LPF/BPF board
Here is what all 4 uBITX LPFs look like as plug-ins. Note that the 6x LPF board is arranged to where you can cut off 1 or 2 of the LPF/BPF positions with no ill effect. 73 Kees K5BCQ
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Kees T
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#58487
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Re: UBITX TX level diagramme
Lawrance, are you using uBITX with BAT54S as mixer diodes ? If you used 1n4148, then your tests could be valid. regards sarma vu3zmv
By
MVS Sarma
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#58486
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Re: K5BCQ uBITX Relay Switched LPF/BPF board
Since most keep talking about the need for BPFs for certain bands, I "guess" the 80m-10m uBITX direction should be a board with 6 filter capability. How about a?basic?dual relay?switched filter
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Kees T
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#58485
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