tag:blogger.com,1999:blog-4774014561040227748.comments2024-03-14T08:19:44.957-06:00KA7OEI's blogUnknownnoreply@blogger.comBlogger539125tag:blogger.com,1999:blog-4774014561040227748.post-73624948887047401212021-12-10T14:54:37.876-07:002021-12-10T14:54:37.876-07:00Where have you been all my life?....or at least th...Where have you been all my life?....or at least the last 5 years, when neighbourhood RFI ended my “radio career”. Thank you for one of the best “hands-on” , real world RFI mitigation website/blog. You have provided the exact type of “homebrew” solutions I have been looking for. I especially appreciate you showing how to gleam the parts from “on-hand” SMPS and electronics. That is especially educational and hope you will do more. <br />Finding the neighbourhood RFI source is just as troubling as getting co-operation from the offender. I would never modify someones offending equipment, but I can at least insure my own home is RFI “clean” and prove “its not me”...here is how it “should”have been designed/built. Joehttps://www.blogger.com/profile/08995516987527086464noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-3132223157639045812021-11-30T15:12:56.986-07:002021-11-30T15:12:56.986-07:00Awesome! Thank you, worked like a charm! I will al...Awesome! Thank you, worked like a charm! I will also point out that my Kill-a-Watt circuit board was traced and drilled for various sized safety cap cases (original cap was 15mm between leads), so the 22mm lead spaced cap I inadvertently received, physically fit perfectly on the board!genesoundhttps://www.blogger.com/profile/15464690163742544676noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-12787919217205097482021-11-26T21:40:23.320-07:002021-11-26T21:40:23.320-07:00This thing is awesome.
I'm a hobbyist with m...This thing is awesome. <br /><br />I'm a hobbyist with many years of electronic junk laying around, and I just built this tonight, not even using any of the same components. And yet it worked. It's one of the only things I've ever built that's worked on the first try. <br /><br />An ingenious, foolproof circuit! Especially since it doesn't require the split primary coils like every other one of these drivers I've seen. <br /><br />Thank you so much! I'll be using it as an ozone deodorizer for the kitchen trashcan <3 Goodbye, smelly garbage! Anonymoushttps://www.blogger.com/profile/09973990921484205400noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-995595640545606752021-11-10T10:48:47.837-07:002021-11-10T10:48:47.837-07:00hi all, have the same problem from my upper neigb...hi all, have the same problem from my upper neigbour's Led lights. I ask him to close his lights in order and then all noise disappear. , he has 5 led unit during corridors, all of them produsing noise but one of them has high QRM , its close to main dore and vy close to my antennas,. I have to uninstall one of them,<br />I will diagnose its driver model and brand than I will try to reinstal new better equal one but need offer abt better brand name who has less noise, which one is good.<br /><br />73<br /><br />TA1D Kadri AntalyaTÜRK-İSThttps://www.blogger.com/profile/15341790184010195685noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-14536994747104579422021-10-30T23:36:38.086-06:002021-10-30T23:36:38.086-06:00Thank you for your instructions. They enabled me t...Thank you for your instructions. They enabled me to repair my Nikon S8100 camera after I dropped it and cracked the LCD unit. I didn't need to remove the 3 screws on the bottom towards the front (in the red cover in figure 1), nor screw E in figure 2).<br />The LCD unit is enclosed in two metal pieces which will separate with careful use of fingers and fingernails. I did use a hairdryer to warm in up in case glue was used - but I'm not sure if that was needed. The backlight with the small flexible connector remains on the one piece of metal. The LCD unit should separate from the other piece. The new LCD unit will have plastic protecting the glass on both sides. Remove the plastic on the backlight side before replacing the LCD. Try to keep the plastic on the front of the display unit until you finish reassembly to prevent scratches. You may need to extend the tab of the plastic sheet with some sticky tape so that you can get it to poke out of the opening in the back panel of the camera.<br /><br />The camera worked again after reassembly, though the flash ready light didn't work - either I didn't get it in the right place before reassembly, or it was broken in the fall. I'm not going to take it apart again though.Andrewhttps://www.blogger.com/profile/17977997934314026914noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-1805899220371965622021-10-24T11:43:24.891-06:002021-10-24T11:43:24.891-06:00I didn't see a question in your comment, but I...I didn't see a question in your comment, but I presume that you are asking if overvoltage might cause damage to the RAM?<br /><br />The quick answer is no, unless the power supply for the entire unit is outputting too-high a voltage.<br /><br />The contents of the RAM, as mentioned in the article above, can be corrupted by too-low a battery voltage in the section "Another reason why your IFR-1200 may be throwing "At" signs". You should, of course, determine if this is what is happening in your case.<br />KA7OEIhttps://www.blogger.com/profile/01153508130273704727noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-34167813591918552021-10-23T16:05:19.273-06:002021-10-23T16:05:19.273-06:00Hello, I have two processor cards received over vo...Hello, I have two processor cards received over voltage, it does not turn on the screen once it is turned on when connecting and disconnecting the output flat cable. The overvoltage caused damage to Ram and the information was lost there? Thanks in advance<br />I apologize if I am told that I am using the translatorAnonymoushttps://www.blogger.com/profile/00322588570184881325noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-70828203907402881342021-08-19T10:58:47.596-06:002021-08-19T10:58:47.596-06:00Thanks for answering. I like to tinker, so I caref...Thanks for answering. I like to tinker, so I carefully took off the clear plastic lens with a razor knife, took the 4 screws out and found the tiny button switch parts floating around in the case. I reassembled the parts and used two part epoxy glue to hold fast. It seems to be working great.Anonymoushttps://www.blogger.com/profile/10929601872507899939noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-13128019306254933862021-08-18T17:22:51.080-06:002021-08-18T17:22:51.080-06:00I've never heard of "spare parts" be...I've never heard of "spare parts" being available for these as these speedos were never even intended to be repaired. <br /><br />The best bet would be to make something yourself (but the rubber seal may be difficult to manage) or find a "for parts" speedo somewhere.KA7OEIhttps://www.blogger.com/profile/01153508130273704727noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-90779053493921422442021-08-16T07:30:58.694-06:002021-08-16T07:30:58.694-06:00I purchased a used polaris 2013 570 rzr. The speed...I purchased a used polaris 2013 570 rzr. The speedometer works but dosen't have the mode button stem. I was using a nail to change modes. Yesterday, I couldn't change the mode anymore, it's stuck on hrs. Can I change the mode switch [button]? If so where would I purchase one?Anonymoushttps://www.blogger.com/profile/10929601872507899939noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-3081203980104333882021-07-26T21:12:03.846-06:002021-07-26T21:12:03.846-06:00Most likely related to:
https://licensing.fcc.gov...Most likely related to: <br />https://licensing.fcc.gov/myibfs/download.do?attachment_key=11355957Axhttps://www.blogger.com/profile/14830318042112772222noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-20497416426674081872021-07-07T12:23:07.396-06:002021-07-07T12:23:07.396-06:00If you own a NanoVNA, you can measure the crystal ...If you own a NanoVNA, you can measure the crystal directly. Typically, the difference between a series and parallel crystal will be on the order of a few kHz - usually too much to "pull" with a reactance (cap or crystal in series or parallel).<br /><br />As a sanity check, put another crystal in the circuit (doesn't matter too much the frequency - but in the 20-30 MHz would be preferable) to make sure that the oscillator is working.<br />KA7OEIhttps://www.blogger.com/profile/01153508130273704727noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-64472079542347316442021-07-06T19:02:29.970-06:002021-07-06T19:02:29.970-06:00You could be right , the Crystal is salvaged from ...You could be right , the Crystal is salvaged from a CR452 std IC910 Oscillator<br />the crystal was removed and tested as some legs were broken on the unit.<br />Crystal worked in the tester ok , but using your circuit it refused to oscillate , using a BC549B AND BUFFER 2n3094 , Found the output not working from the emitter but signal strong from the collector connected to power ?<br />I need to find if the crystal is a series or parallel cut ?199LONGhttps://www.blogger.com/profile/04595237433147262849noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-57626803515916791612021-07-06T08:50:31.471-06:002021-07-06T08:50:31.471-06:00Hallo!
Vom mir ebenfalls vielen Dank für den Tipp...Hallo!<br /><br />Vom mir ebenfalls vielen Dank für den Tipp mt dem Reset! Hat bei mir ebenfalls funktioniert! Wäre ich eher nicht drauf gekommen! Ausgezeichnet !<br /><br />Danke und 73 de DL3SETDL3SEThttps://www.blogger.com/profile/14015001911810764267noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-21724899896542853012021-07-02T17:08:45.962-06:002021-07-02T17:08:45.962-06:00Looks like your suggested edits to wsprdaemon.conf...Looks like your suggested edits to wsprdaemon.conf are now included.KX4Ohttps://www.blogger.com/profile/15709846241012049168noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-90179203847061916532021-06-30T09:50:41.218-06:002021-06-30T09:50:41.218-06:00Ideally, the tuning voltage, when locked exactly t...Ideally, the tuning voltage, when locked exactly to 30.2 MHz, should be 2.0-2.5 volts - more or less in the center of the tuning range/tuning voltage.<br /><br />It sounds as though the frequency is too low when adding the varicap, even with the trimmer capacitor set to minimum. In this case, try moving the trimmer capacitor to be in series with the crystal rather than in parallel with the varicap.<br /><br />Alternatively, in the event that your varicap has more capacitance than you expect, you can put a fixed or variable cap in series to reduce the total capacitance that results. The hazard with reducing the tuning range of the varicap in this way is that it must still be able to adjust the frequency across the expected temperature range.<br /><br />Too-low a total capacitance, the oscillator may not start, so keep this in mind when adjusting the capacitor: Listen to it on an SSB rig when it's powering up to make sure that it starts quickly with minimal chirping. <br />KA7OEIhttps://www.blogger.com/profile/01153508130273704727noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-13744172871576150202021-06-29T20:03:27.026-06:002021-06-29T20:03:27.026-06:00Dear Sir
I have built up a copy of Rex`s Circuit o...Dear Sir<br />I have built up a copy of Rex`s Circuit of the PLL that works up to a point .<br />I am using your design for the 30.2 Mhz Oscillator circuit , but I am having trouble getting it on frequency , with out the varicap in place I hav no trouble tuning it to 30.2Mhz as soon as a varicap is in place the frequency goes down by 20 -30 Hz , I have tried various vari cap on hand but with similar results , Question <br />should I set the initial frequency higher before fitting the varicap ? <br />Bryan VK7KWB 199LONGhttps://www.blogger.com/profile/04595237433147262849noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-42921311388256680342021-06-06T21:42:50.551-06:002021-06-06T21:42:50.551-06:00Thank you, you are brilliant. My killawatt was rea...Thank you, you are brilliant. My killawatt was reading 170+ V and the number was barely visible. I replaced with an X2 and it is working like new again. Best price I found was on amazon with 5 for $4. https://www.amazon.com/gp/product/B083FJ5XQ3/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1<br />Thanks again.Michael Ehttps://www.blogger.com/profile/14489437825241615659noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-44087649511952755372021-05-23T09:16:55.077-06:002021-05-23T09:16:55.077-06:00I do not know of any published frequency-versus-su...I do not know of any published frequency-versus-susceptibility curves for GFIs. My understanding is that the ESUs operate somewhere below 5 MHz, which is well within the range I have observed tripping of my GFIs.<br /><br />Clearly, there is common-mode RF on the power mains cable which, given my assumed limitations of what you can do within the scope of regulatory restrictions, might be a challenge to mitigate.<br /><br />If the frequency is fairly high (several MHz) I would expect that a high choking impedance on the power cord (e.g. a dozen or so turns on a large Mix 43 or Mix 31 ferrite) might reduce the problem. Such would not modify the equipment directly, but it would probably require that this be placed on an extension cord.<br /><br />The other possibilities - such as the addition of capacitors to shunt RF as noted in the article - would, I'm guessing, be out of scope of what is allowed!<br /><br />KA7OEIhttps://www.blogger.com/profile/01153508130273704727noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-14566263087372424972021-05-22T16:26:29.738-06:002021-05-22T16:26:29.738-06:00I am working with an Electrosurgical Generator in ...I am working with an Electrosurgical Generator in a hospital which is tripping GFIs in the department. These ESUs send out RF in the form of current at high frequencies. For some reason the facility has elected to have a GFI in the surgical suite instead of the customary LIM ungrounded system. This article gives me a lot of food for thought as I am struggling to understand the RF tripping the GFIs like this. Do you know any of the frequencies per chance affecting the GFIs to make them trip per chance? I am trying to understand it in a mathmatical manner to be able to engineer against this factor. thanks! Great article by the way!<br />mrstanmrstanhttps://www.blogger.com/profile/16006722905240145727noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-56735604797839775242021-05-14T19:00:48.568-06:002021-05-14T19:00:48.568-06:00I would check every capacitor in the HV supply bef...I would check every capacitor in the HV supply before going any farther - and if you haven't yet replaced all electrolytics with low-ESR, 105C caps, I would do so. In particular, if there was a failure of the capacitor on the +12 volt line feeding the HV inverter (C3432 or C10, depending on the version of the board) all bets would be off when it comes to operating properly.<br /><br />I have seen either the intensity or the focus potentiometer on these units fail, but smoke was involved and it was pretty obvious.<br /><br />KA7OEIhttps://www.blogger.com/profile/01153508130273704727noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-45498908008385528262021-05-14T16:12:03.194-06:002021-05-14T16:12:03.194-06:00Having issues with scope on the 1100s when I turne...Having issues with scope on the 1100s when I turned on I heard a squeal and scope didn't light up, opened up unit and tried again only to see arching and a little smoke on the high voltage board the crt plugs into,, I removed the scope section to investigate, found 1/4 WATT resister burnt and figured crt went bad and took it out, tested the CRT in old RCA oscilloscope and it works just fine, so it's not the CRT,, looking further I found a cold solder joint on the 500k focus pot,, could this have caused the failure?? I visually inspected the high v coil and it appears to look normal. Which I've been told is usually the main causes of failures on these scopes,, before I put out a hundred dollars to replace said coil thought I put this out here, maybe someone can shed some light on this before I go any further thanks. Kevinkevinfitz493https://www.blogger.com/profile/08680891300593020354noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-63876324051484614512021-05-10T07:52:05.903-06:002021-05-10T07:52:05.903-06:00Thanks for all of this detailed review mate! Great...Thanks for all of this detailed review mate! Great job. I tested on of these Chinese craps too in lab and results were a bit better > but also far bellow acceptable level in terms of harmonics, spurious sigs etc. <br />Anyway we tested this unit using 2m / 1,25m and 70cm separate 9-poles BPF in between antenna and radio and finally it was usable. <br />So I am recommending (if someone already got it) to make output BPF...<br /><br />Best regards,<br />PetrPetr, OK1RPhttps://www.blogger.com/profile/11092364724802787693noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-76688596046656936592021-05-03T02:52:18.414-06:002021-05-03T02:52:18.414-06:00Love your circuit and would like to build one up ,...Love your circuit and would like to build one up , at present using REX`s PLL <br />With my Trimble GPSDO . WORKS WELL , <br />I have a Icom CR452 30.2 Oscillator and woul like to use it as the Y20 oscillator <br />but will have to figure out how it would work in your circuit. Bryan VK7KWB 199LONGhttps://www.blogger.com/profile/04595237433147262849noreply@blogger.comtag:blogger.com,1999:blog-4774014561040227748.post-11630890048480279832021-04-25T09:38:55.142-06:002021-04-25T09:38:55.142-06:00Hi Oliver,
I'm surprised that you aren't ...Hi Oliver,<br /><br />I'm surprised that you aren't seeing a bit of external noise floor with just one stage of amplification on the loop - surely SWBC signals are reasonably strong with the amplifier powered up?<br /><br />For other uses, I have a version of this same loop/amp (although the loop is larger) in which there is a DPDT relay that bypasses the amplifier when unpowered: I use this with my FT-817 which has a known problem in that S-meter readings >= S9 along with its "IPO" and "ATT" settings to better-locate strong, local signals.<br /><br />Anyway, the "naked" loop (no amplifier) - which significantly down from a full-sized antenna - does permit hearing a reasonable number of signals on the lower bands (e.g. those that are open these days) so it would be good to make sure that the sensitivity of the loop passes a "sanity check": When connecting a radio to the loop+amp, it should be roughly as good in absolute sensitivity as a full-sized antenna.<br /><br />To answer your question: Yes, you *could* add another amplifier, but in my experience, it shouldn't really be necessary.<br />KA7OEIhttps://www.blogger.com/profile/01153508130273704727noreply@blogger.com