Ubitx v3

net to tell us about a page on his website where he describes his uBitx (V3) mods. Philip G7JUR suggests connecting a 10 microFarad capacitor to the LM386. The sBitx is a 40 watts, fully open source, high performance HF SDR transceiver with in-built popular modes like the FT8, RTTY, PSK31, etc. Given the small number of parts this can be “sky wired” and “shrink wrapped” into a small assembly with fly leads that will fit inside many dynamic mic bodies. Jul 9, 2018 · Lex PH2LB wrote to uBITx. RX: Jul 16, 2018 · v3 Stock uBITx Software Download v4 Stock uBITx Software Download v5 Stock uBITx Software Download KD8CEC uBITx Software Download KD8CEC uBITx Manager Software KD8CEC Manual for v1. Get more I/O ports; Add AGC; Add Mic Pre-amp Gain and/or Compression; Add 160m (or LF or MF bands) Replace Raduino; Add Nextion Colour Touch Screen; Suggestions. com) for around US$10 when on special. This 10W HF Linear Power Amplifier kit has no Surface Mount Components (SMD) to solder. Don ND6T has been tinkering with AGC mods, and has come up with a new solution that gives much high levels of RF compression. This could be very useful for those wanting to stick with the HF Signals latest firmware, while making it easier to view or update initialisation settings, such as calibration of frequency or setting the BFO injection point, in the original firmware. Bought my ubitx kit last year. The orange range wire from the audio connector should be connected to the to the wiper on the potentiometer and the yellow wire to the hot end of the potentiometer. The hardware is from Joe VE1BWV and the software from VU2SPF. Apr 16, 2018 · New AGC system. Double conversion, superhet architecture. ”. The same version of uBITX Manager will work with the v5 Board. Dec 23, 2019 · To run the v6 firmware on a v5 board, you will have to jumper gnd, 5v and the six data lines between the old Raduino and a TFT 2. just received the new ubitx v6. Two problems have emerged with the TDA2822 part: some parts uBITX v6 – Buy the Basic kit. BITX-3-Files Download. 100 memory channels come standard, along with a tunable BFO, selection of VFO A, B or M. His enclosure uses a 3U rack (9 cmx40cmx43cm). It is now the uBITx. 8″ v6 type TFT display to your v3 – v5 uBITx. This mod only involves 5 parts. The first uBITx has appeared with a 2. In reality, transformers and other forms of µBITX – Circuit Description (V4) µBITX Circuit Diagram (PDF) | Raduino Circuit | µBITX ‘s Arduino software. uBITx. The audio pop fix summary will be updated shortly. He has written an article about it here. Arv’s conclusions to date are: Power supply current limiting (2. Includes the TFT Raduino, the basic kit is without the metal enclosure. You could set it up to be variable for only a few volts change to vary the output. Continuing on with the general receiver concept with lessons learned from the minima, the uBitx was published. After pointing out an out-of-date reference on uBITx. 1cU now available. This display, however, has its uBITX v5 – Archived. Jul 9, 2019 · Remote access to your uBITx. com). You can use any 10K logarithmic This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. Feb 22, 2018 · Faulty TX/RX relay. PCB layout for the Bitx20 v3 Board. ). installed nextion 3. The case is a little pricey, but very nicely constructed. 072 BITx hacks uBITx video guide series uBITx YouTube Playlist Dec 23, 2019 · Adding a 2. The µBitx operates on both SSB and CW. Jan 13, 2021 · uBITX V6 review in RadCom. The mic circuit gain on the Bitx V3 is a bit low. It is available in two formats: Changing mic gain by adjusting components in the microphone amplifier. ubitx v6 working. On high SWR the finals can draw up to 2. Assembly of the µBitx transceiver typically takes between 8 and 20 hours. I was experimenting with FLDIGI and attempted to change the frequency by clicking in the 'present freq' window and typing in a value. TN. Posted on December 1, 2018 by Carl Posted in Bitx. Based on Arduino Nano controller and a Si5351 for all local oscillators. The case is all aluminium and easy to work with. A few years ago, at Hamvention, an RSGB representative encouraged me to write a review for RadCom. Feedback from the group suggests that: on transmit it runs around 1. Feb 3, 2018 · Which still seems plenty. USB extender cable. Mar 11, 2019 · Strangely enough he has not seen this behaviour on 15m, 17m or the higher frequency bands, or on the bands below 14MHz. RX: TDA2822 Audio Amp (v3 boards) CW Keying; BCI; Firmware; Display Brightness; Uneven TX output across bands; Modify. TheµBitx produces 10 watts out on 40m and even more on 80m. If you use V2, V3, V4, you do not need to update this firmware. This circuit from Paul K8PD assumes phantom power (~8V DC) is on the Mic Audio line (which is the case with the µBITx). Main uBITX board with mounting hardware. The audio connector’s blue and purple wires connect to the microphone. Simple to build and align. Feb 26, 2019 · V5 uBITx board in production. Use readily available short (100mm) dupont style connectors to link the The circuit and the software is all open source we encourage you to try scratch-building it. The kit is pictured with the Amateurradiokits. Double conversion, superhet . All existing firmware functions for V3 and V4 are available on the V5 beta. Enter menu. A 2A fuse on the TX Rev: 1 C244 c 45 ooop IOOOp 2N3904 ct56 C151 0. You may freely reproduce this circuit as long as nothing is changed and the entire accompanying text is reproduced along with it. The part has been replace in the v4 board currently shipping by discrete 2N3904/6 transistors. 2017-04-10 1026 words 5 minutes. 1 u 6 TXB C15 2N3904 I TX (c) Ashhar Sheet: / File: bitxgr2. Connect the yellow wire to the hot end of the volume control. Others have seen similar phenomena on different bands, some with the spurs appearing on starting TX and then disappearing. Alternative software. in metal case, and features the stock firmware and display module. AGC KIT For Bitx And uBitx. 4-1. We would like to show you a description here but the site won’t allow us. 2: Wiring up the Microphone. Minimal controls. PA powered by buck boost at 13. W0EB/W2CTX ubitx_V2_00R Download. Oct 29, 2019 · 4) Connect the minus line of power supply line to the ground. 8″ TFT display to your existing µBITx. Jun 16, 2019 · There has been a bit of BITX20 IO Groups list chatter about the winner in ND6T’s AGC circuit (with RF gain control). Rated 5. However, there will be no soldering required as all of the connectors and related componentry either plugs in or has been built in to the board. “You want to be very careful when adjusting IRF510 gate bias trim-pots, take it too far and the IRF510’s might be trying to dump 100 Watts or so. 8” TFT display. Mar 22, 2018 · Wait for the menu to exit automatically. Simply remove C50, C63, R52 and R66 on the main µBITx board. There are currently three software altentaives available – all are open source and can be downloaded for free: KD8CEC v1. Support is offered only through the BITX20 group which you can visit here. 01uF x 2 bypass capacitor to the power connector. uBitx v2. It’s a simple circuit and replaces the S meter circuitry, too. Allison KB1GMX says “Both cases come from the same source, heating in the amplifier usually the pre Microphone options. installed new filter and coil mods for harmonics and spurs. Note that HF Signals website has not yet been updated. Original Bitx20 v3 Board. Zerobeat the WWV carrier. Order Basic µBITX v6 for $160 USD. uBitx v3. 6 MHz that was down only 23dB from the fundamental. 3 original firmware (published on may 23 2018) to include communication with KD8CEC memory manager. But if you push it much higher than that, the mic circuit will cause some distortion. Jul 31, 2018 · In ubitx_20. The fully assembled kit with Raspberry Pi 4, 2GB and the Raspberry Pi's own 7inch capacitive touch Aug 3, 2018 · The nano and the serial connections to the Nextion doesn’t have the agility to provide a full blown waterfall display, but a real time display of signals around where you are currently tuned is still pretty impressive. net Aug 10, 2019 · The ARRL has published a very positive review of the µBITx transceiver completed by the ARRL Labs team in their September issue of QST. If you tap on one of the VFOs, Fast tuning gets enabled where each step of the tuning encoder results in a jump of 50 KHz. Adafruit audio compressor in mic line with chokes to eliminate RF feedback. 061 KD8CEC Manual for v1. SSB and CW. great receive on it was listening to w1aw on 5 ft of solder temporarily hooked up to The Excellway® EF01 Electronic Project Case is a popular choice (purchased through Bangood. Mar 27, 2018 · Don ND6T has recently installed a 20 dB RF AGC modification in the BITX40. This should be reasonably self-explanatory as the same data lines are used on the standard 1602 display and the ILI5341 Display. Dec 25, 2019 · Digital interface kit for your uBITx. 8v or you can leave it off for direct 5v input. 01 Download. 7) To prevent common mode noise, add 0. A through-hole single-side version measuring 17X38 mm. link to schematic. UPDATE. Apr 2, 2019 · I received the feedback from a thankful beta tester and tested it myself by converting my uBITX v3 to v5 but I was not sure. The µBITX presents some challenges with RF AGC system design: There is no RF preamplifier to use as a voltage-controlled attenuator, it is broadband and includes no tuned circuits in the receive path Mar 21, 2018 · Antenna Tuners for the uBITx. 4) Connect the minus line of power supply line to the ground. He suggests it is unfortunate that specifications for ATU’s usually do not Apr 10, 2017 · bitx20 v3 build – vfo - awsh. Wire up. There have been quite a few posts recently on the BITX20 list about remote access to your µBITx. 2 R1. Jacob AG7CT has documented the steps he takes to calibrate his µBITx: Tune to WWV on the dial. The µBITx comes with an electret microphone capsule, and the circuit is designed to support this (with “mic bias” of around 9v applied to the element). 072 BITx hacks uBITx video guide series uBITx YouTube Playlist TDA2822 Audio Amp (v3 boards) CW Keying; BCI; Firmware; Display Brightness; Uneven TX output across bands; Modify. Bring on Step 5. Stability has been mostly solved by going with Si5351 and Si570 digitally controlled local oscillators in modern HF receiver designs. The +ve end should go to pin1 and the -ve end of the capacitor to pin 8. net compares products and The active BITx community has quickly responded with several software developers offering firmware that upgrades our stock uBITx. Dec 13, 2019 · v6 uBITx released! Ashhar Farhan VU2ESE has announced today the release of the v6 uBITx transceiver. Oct 13, 2019 · Dynamic mic preamp runs off “phantom power” from uBITx. I put together an arduino nano, an si5351 breakout board, and a small oled display on a breadboard. Push-pull driver and push-pull finals, for high linearity and low harmonic content. Most time is likely to be spent on creating the hole for the display. 2A approximately. This setting does produce a “gap” in AGC effect at the bottom end, but this Output Xformer replace with 2:4 on BN43-202. Ashhar Farhar reported on 6 February 2019 that HF Signals has pushed the uBITx v5 into production. Bitx-Version-3-Linear-Amplifier-Assembly Download. An SMT board measuring 18X31 mm, with SMT components that are 0805 in size. 1u. Pi-network for dipoles. 00 out of 5 based on 1 customer rating. Use a 50 ohm pad. Step 4. Mar 13, 2019 · The mod can be placed in the same position on the v3 board as in the v4 design, using a simple Dupont header as shown below, but there are other ways of achieving the same result. Note that a Mitsubishi D16HHF1 in push-pull requires a higher bias current setting (perhaps 250 mA or 300aA). Tapping the tuning control again will simulate pressing that button. Introduction to tuners and tuning. Then press the encoder again and in turning the dial you should see the additional menu items displayed. Many constructors may wish to substitute the supplied potentiometer, because of its non-standard shaft size. The case will accept either of the Bitx40 or µBitx kits. This is a very nice build, and he has some good ideas. Additional parts were already on hand. Mine was working then started to become intermittent. Make sure you order a 2. The display provides full touch control along with physical optional buttons. 10 0. Ricardo has found it to work perfectly removing all popping noises in both transitions. Two problems have emerged with the TDA2822 part: some parts Jan 26, 2018 · Conclusions about protecting the IRF510 devices. Constructors can use this element and a press-to-talk switch to create their own microphone. . Feb 3, 2018 · Typical current draw on the uBITx. You can search online for solutions. Marco – KG5PRT suggests, “It’s kind of crude, but you could power the entire radio with 24v. Arv K7HKL suggests the type of antenna tuner depends on the type of antenna: L-network for end-fed or high impedance antennas. R N Harp needed a regulated power supply to run his µBitx and a couple of arduino kits, but he didnt feel like shelling out hard cash for a $100+ power supply unit. Shipped via DHL (warning: Some European customers may face customs duty). Attach the knobs to the Tuning Encoder and the volume control. I’ve always felt this RSGB publication strikes the right balance of technical information and human interest. link to download. A number of examples of homebrew microphones can be found on the BITX20 list. Contents of the Full uBITX v6 kit: Main uBITX v6 board1. There are a number of ways to achieve this, but Jens (KM6ZJV) has provided a useful summary of how he has achieved this using a v5 µBITx connected around the clock to a Raspberry Pi 3 used as an FT8 monitor. Assembly. I do tests with both a local receiver and remote SD May 22, 2019 · My uBitx v3 has been working fine and I added a usb audio card and 2 port hub with a separate PSU, this has also been working very well. Jun 24, 2018 · The mod can be placed in the same position on the v3 board as in the v4 design, using a simple Dupont header as shown below, but there are other ways of achieving the same result. 200 for uBITX All Version (include v2, v3, v4, v5) I did the firmware work for v5 when uBITX V5 was released, but I release it now. Glenn VK3PE suggests, “For anybody trying to get their uBITX to work in Tx mode. easy build and installed all new relays axiom. Aug 21, 2019 · Rick KN4AIE installed his uBitx V3 in a Cheval case (see previous post) and later added the JackAl mod. He gets 3v, 5v, and 12 volts. See full list on ubitx. David N8DAH is now producing a very handy digital interface kit. A General Coverage HF transceiver kit – No soldering required. He also observes that this solution is the most “healthy” for the PCB as no cuts are required. Use a 12v regulator for the receiver and a LM350 for a variable regulator to the PA. radio works as described. Watch on. ­AGC Kit for Bitx And uBitx and any other tcvr or receiver. net compares products and Dec 14, 2023 · The sBitx v3 board is a full 25 watts radio, with robust IRF510s in the final. Greggory N5WLF observes that he gets in the range of 1. Method 4: Vary the Power Supply Voltage to the finals. TDA2822 Audio Amp (v3 boards) CW Keying; BCI; Firmware; Display Brightness; Uneven TX output across bands; Modify. Turn setup on. Farnham says the input to the first mixer should be around 150mV peak. Everything fit nicely. This will give a bit more gain, and bass. Check his page out here Feb 22, 2018 · Reference. Aug 12, 2018 · New release of VU2SPF firmware v3. Reenter menu turn to and select calibrate. 7 K Ohm. net compares products and Salvaging a computer power supply to power your uBITx. Linear amp, uBitx News bias current, VU2ESE. Saved searches Use saved searches to filter your results more quickly Jun 23, 2019 · Salvaging a computer power supply to power your uBITx. The kits are available for: US$15 unassembled or US$20 assembled. com (formally hfsigs. Most QRP rigs are intended for either phone or CW and not both. µBITX Circuit Diagram (PDF) | Raduino Circuit | µBITX ‘s Arduino software. 5) Connect the minus line of BITX40 main board to the chassis ground. 5. A new version ofSP Bhatnagar VU2SPF firmware for the low cost MCUfriend TFT with Touchscreen based VFO + BFOs is out now along with an illustrated manual. RESULTS: 30W on 80 and 40, 20W on 20. Most QRP rigs only put out 5 watts (or less). Aug 31, 2019 · As built, his V3 uBitx was marginally compliant to US FCC rules on 80, 40 and 20 meters. net compares products and Jan 30, 2018 · v3 Stock uBITx Software Download v4 Stock uBITx Software Download v5 Stock uBITx Software Download KD8CEC uBITx Software Download KD8CEC uBITx Manager Software KD8CEC Manual for v1. Volume control knob. Above 20m the output was messy as a result of lower frequency spurs. The dimensions of this case are 200x175x70mm. Instead, he modified an ATX power supply from a dead PC. I’ve got the main bitx board built enough to test, so now I need the bfo and vfo. Aug 6, 2019 · Output Xformer replace with 2:4 on BN43-202. All bands are selectable from the front display which is a Jul 6, 2019 · Features: 10W output from 2 to 30MHz, using 12V Supply. Generously-sized heatsink, will not overheat even on continuous 100% duty-cycle modes. I modified some of the vfo code I’ve used before and soldered Feb 3, 2018 · Typical current draw on the uBITx. This board (minus the Raspberry Pi) is now available, ex-stock for $180. Bias voltage shutdown on high current (3A) seems to work. (c) Ashhar Farhan, 2019 MIC. 1 uF × 2 bypass capacitor to VDD of BITX 40 board. all bands ssb,cw. Because this is a Wiki anybody can contribute to the effort. Use a small srewdriver to tighten the mounting screws on the side of the knobs for proper grip on the the spindles. Encoder with presoldered cable. An initial 100 boards had arrived so they may run out quickly (reminding us of the v3 board shortages of 2018). 8″ ILI9341 touch panel display. net compares products and Ian KD8CEC has announced a beta version of his firmware (Version 1. The TDA2822 is the audio amplifier part located on the v3 main board of the µBITx. awsh included in Ham Radio. I received the feedback from a thankful beta tester and tested it myself by converting my uBITX v3 to v5 but I was not sure. sch 2N3904 0 lu Far han 2017. 00. Reduce R63 from 100 Ohm to 10 Ohm. Use readily available short (100mm) dupont style connectors to link the Apr 24, 2018 · uBITx assembly wiki page. 2 touch screen display. Jun 2, 2018 · A demonstration of the different effects on transmit audio that adjusting the BFO of an SSB transceiver. 1. Release CEC Firmware v1. 8 amps depending on the SWR. He has not installed it in the uBITX yet but intends to do so soon. Some people will want to guarantee that their computer is fully isolated from their rig and will make or buy interfaces (Signalink, EasyDigi, etc. 200 Supports uBITX v5. Previous. Upto 10 watts pep on lower HF bands, dips to 5 watts on 28 MHz. net recommends Mods & Fixes; uBITx. 2-stage amplifier provides 26dB of gain. Driver impedance to IRF510 gate should be quite “stiff”. Apr 16, 2018 · Connecting your µBITx can be done in a number of ways. net recommended mod to fix the audio pop. The push-pull driver stage uses two BS170 transistors in the amplifier design used in the TDA2822 Audio Amp (v3 boards) CW Keying; BCI; Firmware; Display Brightness; Uneven TX output across bands; Modify. Others are quite happy to wire up a cable for USB control and another for the audio in/out. Mounting screws, nuts. Most BITX automatic gain control schemes use the audio output to apply control of the input of the audio power amplifier. He plans to use the AGC voltage as an s-meter input. net to wire up diagram faults on the HF Signals website, Patrick W7PEA has set out to develop the Wiki (already on the BITX20 IO GROUP website ), starting with a more fully developed Wire Up and Assembly Guide. This display, however, has its Remi F1MQJ has m odified the manufacturer’s v4. Dec 23, 2019 · Adding a 2. Jun 8, 2019 · The amp provides 26dB gain with +/- 1dB gain flatness from 2 to 30MHz. Dec 1, 2018 · My Original Bitx 20 (v3) from Sunil. T-network for medium to low impedance antenna. 6) Add 0. There are a number of small transformers to be wound, and assembly requires care and patience. 8V the rest of the board by 12V battery. No schematics are known to have been published. The ubitx v6 has a few shortcuts: If you tap on the tuning control, you can move the focus on the screen from one box to another. This is the most “FT-817 AGC” like, from his perspective. Aug 3, 2019 · Rick KN4AIE installed his uBitx V3 in a Cheval case (see previous post) and later added the JackAl mod. org. If you are using the Excellway EF01 enclosure, you should consider purchasing these rather nice 3D printed TDA2822 Audio Amp (v3 boards) CW Keying; BCI; Firmware; Display Brightness; Uneven TX output across bands; Modify. Tuning knob. It also provides very good access with both top and bottom covers and front and back panels removable. 12) for the uBITX V5 board. This version (3. There are changes that you can make to components in the µBITx microphone amplifier circuit to increase (or reduce) the gain. RV1 adjusted to reduce output to 15W. These are readily available on eBay and AliExpress for under US$10, which is half the cost or less than a Nextion display. So fewer people complain of overload but AGC is a common wish list item. 8 inch display. Use a low resistance (4. uBITX Version 6 HF SSB and CW Transceiver Full-Kit - MBITX-V6. TFT – Raduino Board with Display with mounting hardware for the front panel. January 13, 2021 Thomas Witherspoon 7 Comments. This is a Gordon Gibby KX4Z design, and it features: On board 5v regulator that you can power from 12-13. uBitx v4 Jun 13, 2018 · v3 Stock uBITx Software Download v4 Stock uBITx Software Download v5 Stock uBITx Software Download KD8CEC uBITx Software Download KD8CEC uBITx Manager Software KD8CEC Manual for v1. ino it shows as: int sMeterLevels [] = {0, 5, 17, 41, 74, 140, 255, 365, 470}; The values in the array are the measured values on the analogue input (defined as A7 above) at which we step into a higher “stage” and can go from zero for zero volts to 1023 for a 5V DC value. He foresees his pr ubitx, only being used with the raspberry pi on digital modes. You can directly buy a Raspberry Pi Zero 2 W and have a full SDR running for less than $200. The easiest way to increase mic gain is to change R63 from 47 ohms to 22 ohms or lower. Using 4 of flat head, 6 mm, M3 screws, attach the Display board (The TFT Raduino) to the front -panel. Nov 27, 2019 · This video shares my version of homebrewed uBITX V3 QRP Transceiver. I ordered the uBITX V5 and delivered the correct uBITX V5, so I made a little more fine-tuning. 072 BITx hacks uBITx video guide series uBITx YouTube Playlist The TDA2822 is the audio amplifier part located on the v3 main board of the µBITx. Connect the orange wire to the wiper (middle lug) of the volume control. 1cU) provides the following new features: Lower and Upper limits for displays of S-meter and Power meter. A 2A fuse on the TX Jun 11, 2018 · The uBITX runs without an RF gain control and was optimised for a decently high overload point. Ion VA3NOI has two versions of an ND6T AGC circuit board designed. 6. Dec 6, 2019 · LM386 mods (v5 uBITx) The v5 uBITx has an LM386 for the audio amplifier stage. About V1. The manufacturer participates in this group and has done troubleshooting to resolve customer setup or defective concerns. The easiest place to access is to solder to C75. TheµBitx is near complete, with the main board pre-assembled and tested, so there is less that can go wrong for the home constructor. 7 ohms) in series with each IRF510 gate lead. 8 amps current draw on transmit, SWR depending and asks if this correct. The version 3 schematic is the version of the first production board from HFSignals. The other feature that is present in the Nextion display version of this arduino add-on, is a CW decode function. S9+20 2,300 Saturation of both uBitx and AGC (visible in audio FFT, but not really audible) S9+30 2,400 Audible saturation of uBitx and mostly of AGC. I would key the Mic PTT switch and the display shows it’s in Tx mode, but with no power out. For example, on 15 meters there was a spur at 2. The circuit is exactly the same on the main board. It is not difficult to add a 2. To increase gain you could try making the following component changes: Increase R65 from 1K Ohm to 4. Connect the green wire to the ground tab of the volume control. 5 to 3A) seems to work. The raspberry pi is loaded with WSTJ-x for use on the FT8 and FT4 modes, and for FL-DIGI for PSK and RTTY. The rig mainboard was obtained from Ashhar Farhan VU2ESE with the price of USD139, anoth Oct 29, 2019 · 3) Insert high frequency choke of about 100 uH in the power line of Arduino. Feb 26, 2019 · Ubitx v1. The BITX40 and earlier models used the LM386 as an audio amplifier, so this board was new to the µBITx. The majority of the time is spent on selection of the enclosure, knobs and power supply, and in creating holes for insertion of components on the front and back panels of the enclosure. Building-a-Bitx20-Version-3 Download. Oct 12, 2019 · The project includes a dual power supply with a built-in power supply and battery power for portable use. Fully Assembled and tested sBitx with microphone. . ( 1 customer review) $ 22. “Tracing signals etc, I found that the K1 changeover relay was not switching 12V to the Tx Aug 4, 2018 · Release CEC Firmware v1. Assemble the µBITX transceiver in an hour with just a screwdriver! A general coverage, 10 watts HF SSB/CW transceiver kit with features you NEED for operating ease, convenience and versatility. Substituting the potentiometer. I’ve been a massive fan of RadCom since I lived in the UK. In the rare instance of a defect, it would be handled with the manufacturer. 1 You may freely reproduce this circuit as long as nothing is changed and the entire accompanying text is reproduced along w ith it commercial production of thi s circuit is prohibited without permission This 15 component audio pop fix from VA7AT has been built by Ricardo, LU7CRA. May 3, 2018 · Release CEC Firmware v1. fw jb vr oz qv et bm ro wd bj