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  • anne's Avatar
    Today, 19:58
    With 11 Ohms limiting resistor the array drawa 90 mA and there is 1 V across the resistor. Currently running "smoke test".
    7 replies | 84 view(s)
  • anne's Avatar
    Today, 17:36
    I woudl not say you have made an error / wrong assumption when it comes in connecting serial / parallel LED array. You are just working what is known / given , same as I. This whole exercise did not started as theoretical application of Ohmís law, but as an experiment with real limitations, including wallwart DC supply. I need to point out that the specification for the LED is not written in stone, just my best guess. I really do not have real data what is maximum current before LED became "fast blow fuse". Here is the latest. With the fan running @13V , drawing 55mA I added 100 Ohms limiting resistor connected to 3 LED's in series.
    7 replies | 84 view(s)
  • brandon lind's Avatar
    Today, 16:50
    Admittedly, i made two critical errors in my first response. The first error was suggesting a single resistor for the entire array. Diodes in parallel to other diodes have the strange ability to unevenly pass current. This means every parallel path of LED lights will need an individual limiting resistor. The other error i made was making the assumption your supply was regulated. Being it is typical for wall worts to be rectified sine waves with no regulation, the unloaded peak voltage and the loaded RMS voltage prior to rectification will be different ~ hence the 16v you see with nothing connected This needs to be taken into consideration when designing the system.
    7 replies | 84 view(s)
  • flboy's Avatar
    Today, 15:47
    flboy replied to a thread Wires-X HRI-200 Question in Yaesu
    BTW, if you do not care about setting up your own room or analog connection on Fusion, no need for and HRI-200 with the HRI mode in new capable radios. Sent from my SM-N970U using Tapatalk
    2 replies | 192 view(s)
  • flboy's Avatar
    Today, 15:45
    flboy replied to a thread Wires-X HRI-200 Question in Yaesu
    I believe both are true. The newer FT-400, FT-3 and FTM-100 an FT-2D with latest firmware can go into HRI mode and make a direct connection. They can also provide a node access where you can use another mobile Fusion capable radio to connect. I use a FTM-100 in my pickup and can hit my FTM-400 from cross town similar to a repeater and connect to Fusion via the FTM-400 and PC internet connection. I hope this helps. KE4EVL Sent from my SM-N970U using Tapatalk
    2 replies | 192 view(s)
  • anne's Avatar
    Today, 15:01
    I realize I am getting ahead and answering / posting before my posts are approved. I run another test to get better feel for the DC supply. My ultimate goal is to pass air over the array. I am currently using 12V DC fan and the DC supply output drops to steady 13V @ 55mA I think I will size the limiting resistor to pass 150 mA to the array.
    7 replies | 84 view(s)
  • eddiek's Avatar
    Today, 14:59
    eddiek replied to a thread phasing harness question?? in Antennas
    Put that antenna on the VNA and started cutting the dipoles - your answer is is correct, didn't matter, least I could tell. My return-loss is in the low -30's dB. BW is about 25-30 Mhz wide. The ant really started to resonate when close to design freq. Take that any day...
    2 replies | 84 view(s)
  • R2D2's Avatar
    Today, 12:05
    R2D2 replied to a thread yeausu ft8900 in Yaesu
    Post a picture of what you are talking about? Center Button where? Center Button in the middle of the display is the function button. Button to its left is the scan, button to the far right is also scan.. Radio squelch needs to be closed for the radio to scan. The radio will function without the microphone. Unplug the microphone, close the squelch, press the scan button. Find yourself an Elmer!
    9 replies | 263 view(s)
  • R2D2's Avatar
    Today, 12:01
    R2D2 replied to a thread phasing harness question?? in Antennas
    1 inch one way or another, unless you are cutting the antenna for an exact frequency with a high q antenna isnt going to make any difference.
    2 replies | 84 view(s)
  • anne's Avatar
    Today, 03:21
    Sorry , your very informative analysis and actual measurements do not agree. But I do appreciate you spending your time on it, for real. I think the real problem is figuring out how "hard" these DC supplies are, AKA how does the output hold under load. Also - LED blows very fast when the current is not limited IMMEDIATELY ! I have replaced limiting resistors - two 1k resistors in parallel with four resistors in parallel. Now I am reading almost 9V across the array and almost 20mA of total current. I can accept the 9V , but 20mA is way off the scale !
    7 replies | 84 view(s)
  • rick619's Avatar
    Today, 02:45
    rick619 replied to a thread Mobile Radios WTF Does this mean? in Amateur Radios
    I've been using Chirp and have the cable. Mostly using it to add in repeaters of areas I will be. I was definitely appreciative of being given the radio. Seems like exactly what I need without being too fancy. The screenshot of the manual I was trying to post is the notice at the bottom of page 23. Don't think I can post attachments because it's a new account. I was just trying to understand the gist of the notice. Something about frequency mix and an equation.
    6 replies | 221 view(s)
  • brandon lind's Avatar
    Yesterday, 22:59
    Since the voltage drop remains the same across an LED bulb as the current through it changes, you subtract the LED voltage drop from the supply voltage to obtain the voltage on the resistor. (and thus the current via ohms law). Three 3v LED's in series would be a total of 9v across the string. At 30mA per series LED string, you pull 300mA having 10 of those in parallel. In other words, you have a total of 9v drop and 300mA draw through the entire network of lights. That is too much for that power supply. Given that the addition of a limiting resistor to further lower the brightness will increase the loss, its likely that trying to limit the current further with a resistor will simply shut the lights off. Step one, get a more powerful supply. For simplicity sake, lets do the math on just one 3v 30mA LED connected to a 9v supply. 9v - 3v = 6v across the load resistor. if we want 30mA through a resistor with a 6v drop, 6v / .030A = 200ohm. And the power rating of that resistor is 6v x .030A = 0.180W. This...
    7 replies | 84 view(s)
  • Grahamwms's Avatar
    Yesterday, 22:19
    Grahamwms replied to a thread yeausu ft8900 in Yaesu
    I've just ordered a new cable for the microphone will keep you updated when I receive it.
    9 replies | 263 view(s)
  • 5B4AJB's Avatar
    Yesterday, 22:18
    are we allowed to write a program to work this out?
    7 replies | 84 view(s)
  • anne's Avatar
    Yesterday, 19:55
    Given power supply specification Nominal ( per label ) spec 9V /200mA Wallwart transformer / DC supply load specification LED "spec" forward voltage 3 V max current 30 mA
    7 replies | 84 view(s)
  • eddiek's Avatar
    Yesterday, 16:31
    Hello everyone! Here's an overview of what I'm attempting to do: 1. Establish reliable communication in a very mountainous area. 2. The area I want coverage is roughly 9,000 sq Miles (a square with a base of 100mi, and height of 90mi). 3. The terrain is very mountainous, with mild-to-medium vegetation cover; similar to forests you would find in the pacific northwest. Equpiment: R/T: Harris PRC-150; RT-1694D
    1 replies | 97 view(s)
  • 5B4AJB's Avatar
    Yesterday, 15:14
    5B4AJB replied to a thread yeausu ft8900 in Yaesu
    also, just because it's a Yaesu mic into a Yaesu radio, with the right connector on it, doesn't mean it's wired right - I still reckon' you have a loose wire...
    9 replies | 263 view(s)
  • eddiek's Avatar
    Yesterday, 14:32
    Hey team, First post, wanted to ask if any one knows the answer to this.... Building Turnstyle antenna and the connections to the dipoles are using "pig-tail" wires launched from the end of the coax phasing harness. About 1" long. Do you include the "pig-tails" as total length of coax with my calculations? Kinda guessing it's an impedance bump and who knows what that impedance is.
    2 replies | 84 view(s)
  • generein's Avatar
    Yesterday, 03:46
    Guys I want to use an unused chimney in the building to run some coax to a roof mounted Diamond X200A. I can get some LMR400 and drop it right into my office through this chimney pipe. VHF to start, will work on different antenna for HF later. Do you see any interference with this metal chimney pipe? I think it is aluminum but it might be steel/iron. I will investigate. If no interference it is like someone ran a 6 inch conduit to my home office just for Ham purposes! Any input is appreciated. Gene KJ70GV
    0 replies | 78 view(s)
  • generein's Avatar
    Yesterday, 02:41
    I am now listed! I can start shopping for the right radio(s) and antenna! Will probably start with the repeater on the opposing peak with a triband HT to get the hang of it and then need to figure out my antenna situation in this mountainous valley for HF. Thanks for the advice people! KJ70GV Gene
    5 replies | 712 view(s)
  • R2D2's Avatar
    Yesterday, 00:07
    Why are you here then? Radio is a hobby, it is a learning experience, its not something you can learn all in one day or week or month or year or even 10 years.. Its dynamic, it changes all the time.
    15 replies | 508 view(s)
  • R2D2's Avatar
    Tue 2nd Jun 2020, 23:51
    R2D2 replied to a thread Mobile Radios WTF Does this mean? in Amateur Radios
    The 8800R should be able to save frequencies / PL's in banks. Say you live in Western Pennsylvania and you want to travel to Eastern PA or New York state or OHIO, you can program the radio with separate repeaters in each bank and when you cross the line and go out of range of one set of repeaters you can switch banks and open the other programming with the different PL's and operate on those repeaters without having to manually edit the frequencies / PL's. You can also choose to monitor by name as well as by frequency on the display. The Yaesu is quality compared to the TNT style radios which is crap. You get a much better front end and a more durable final transistor with fold back. You should thank the person that GAVE you that radio, its worth at least $250.00
    6 replies | 221 view(s)
  • R2D2's Avatar
    Tue 2nd Jun 2020, 23:46
    R2D2 replied to a thread Mobile Radios WTF Does this mean? in Amateur Radios
    Yaesu FT 8800 is a dual band radio. Designed to operate on amateur radio frequencies. Both sides of the transceiver scans independently on either band. It can scan 2 meters or 70 cm simultaneously. If you are transmitting on either band and the opposite side of the transceiver is in the same band it will mute the other half of the radio until you stop transmitting to protect the front end of the other side. The best programming software i've found is G4HFQ. You can purchase a programming cable online for about $15.00 The Yaesu programming doesn't work very well and doesn't allow you many editing options.
    6 replies | 221 view(s)
  • Grahamwms's Avatar
    Tue 2nd Jun 2020, 21:05
    Grahamwms replied to a thread yeausu ft8900 in Yaesu
    Hi checked the lock and all that it's basically all the buttons except the middle set button
    9 replies | 263 view(s)
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