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  • WZ7U's Avatar
    Today, 04:45
    Balun is only to remove common mode current from the feedline. Although transformer ratios higher than 1:1 can alter how swr appears to the radio. This is a very complex topic worthy of a better treatment than is likely to get in this thread. Do some research on baluns on the web; this should keep you busy till spring easily. You're going to have to adjust the vertical element to get the swr where you want it. Where is it resonant now? The basic rule of thumb is high on the higher frequency, shorten. High on the lower frequency, lengthen. That antenna came with tuning literature, didn't it? I wonder how the hairpin match looking thing plays into all this...
    2 replies | 98 view(s)
  • brandon lind's Avatar
    Yesterday, 22:46
    Took two and a half weeks to get my call sign, and that was without a shutdown to slow things.
    7 replies | 297 view(s)
  • JohnD's Avatar
    Yesterday, 20:55
    I believe you will have to adjust length of elements.
    2 replies | 98 view(s)
  • Ibtissam's Avatar
    Yesterday, 20:47
    Hi Steffen, what was the radio operating mode, USB-D or FM?
    2 replies | 2012 view(s)
  • Richierich's Avatar
    Sat 19th Jan 2019, 19:47
    Put my 10 meter hygain super penetrator spt 500. Followed the instuctions to a tee. But not to the end. I assemblied and put on the roof leaving off the radials and installed them lastly. So ran my coax rg8x to radio Stryker Sr 955hp and turned it on. Now I see I have a 3 to 1 Swr on all freqs. So now I read the last page of installing antenna about tuning it. So my question is this I've read about a ugly balun to help with swr. Can I use that for a solution or do I have to remove antenna and tune it by shortening it or lengthing? Then put a ugly balun? Thank You Very new to this Rich
    2 replies | 98 view(s)
  • double bogey's Avatar
    Sat 19th Jan 2019, 02:44
    I passed my test on January 10th and am awaiting my call to appear also. Not to be political, but this needs to be settled, and I can wait.
    7 replies | 297 view(s)
  • VIEGAS's Avatar
    Thu 17th Jan 2019, 22:15
    VIEGAS started a thread Base Radios dx-sr9 omnirig file in Alinco
    Hello People We at ARRLx, a Portuguese Radio Clube, have a DX-SR9 Alinco Rig, but we can't link the rig to computer , we use the LOG4OM software. Can anyone have the file that we need? or can you help us? Regard's
    0 replies | 71 view(s)
  • Obed's Avatar
    Thu 17th Jan 2019, 11:56
    Obed replied to a thread Hi all in Introduce yourself
    welcome to the forum and back to the hobby.
    1 replies | 89 view(s)
  • brandon lind's Avatar
    Thu 17th Jan 2019, 05:25
    brandon lind replied to a thread Base Radios IC-745 No RF output in Icom
    That is interesting, I was unaware of the fact Q1 was burning out. It is possible that the replacement has the mounting tab connected internally to the emitter pin and may need insulating mounting hardware like mica or a sheet type silicone heat sync material and ceramic screw support. If the mounting tab is internally connected to the emitter pin, directly shorting it with the mounting screw bypasses the emitter resistor completely! The emitter resistor is CRITICAL. The base-emitter junction wants to stay at about .7v, without the emitter resistor to take up the rest (1.2v - .7v = .5v), it will saturate and dump as much current as it can through the device.
    14 replies | 558 view(s)
  • KB4MSZ's Avatar
    Wed 16th Jan 2019, 20:23
    KB4MSZ started a thread Handheld Radios VX-8DR Dedicated Volume Control in Yaesu
    One of the main complaints I read about with the VX-8DR (and other newer Yaesu HTís) is the lack of a dedicated volume control. I donít know if this would apply to other Yaesu HTís, but with my VX-8DR I accidently found that the main knob can be assigned to control just volume. I did this by pressing the VOL button and then pressing the F button. The volume level indicator will blink as it usually does when adjusting the volume. But with the right combination of F key and VOL key the volume level indicators will continuously blink. Now the radio is in volume control mode with the main knob. Be sure to have the desired memory channel(s) already selected as the main knob no longer controls memory selection. I have managed to turn this feature on and off a number of times and while I still havenít pinned down exactly what combination of F and VOL keys set it up, it does eventually work. I have never read of this feature in any of the Yaesu manuals. After powering down and restarting the radio this feature...
    0 replies | 103 view(s)
  • spbrhs07's Avatar
    Wed 16th Jan 2019, 20:18
    Baud rate is good. Oscilloscope showed the signal going to the transmitter, so the code is good. Turns out the data pin on the HX1 was bent backwards and not plugged into the breadboard... :hopelessness: So basically it was sending empty packets...
    3 replies | 130 view(s)
  • Robbo1961's Avatar
    Wed 16th Jan 2019, 16:03
    Robbo1961 started a thread Hi all in Introduce yourself
    Hello there. Been licenced many years but only been back on the scene a couple of years. Into D-Star and monitor Ref 001C and 030C. Looking forward to picking up more info on radios and digital working.
    1 replies | 89 view(s)
  • Dale Paul's Avatar
    Wed 16th Jan 2019, 15:41
    Dale Paul replied to a thread Base Radios IC-745 No RF output in Icom
    I would like to extended my sincere appreciation for your assistance. I think I have the problem narrowed down to Q1, as it keeps burning out. When I ordered that transistor it was cheaper to order 10 of them, due to the shipping cost. 73s and you have a safe year.
    14 replies | 558 view(s)
  • brandon lind's Avatar
    Tue 15th Jan 2019, 17:46
    You might want to consider a different antenna before you fly it. A half wave MONO pole is ANTI-resonant. If you have the space for a half wave, why not a DIpole? You can incorporate one quarter wave element into the balloon-to-payload tether and the other quarter wave element hanging below. Maybe that infinite SWR is shutting down the transmitter immediately through a protection circuit....
    3 replies | 130 view(s)
  • 5B4AJB's Avatar
    Tue 15th Jan 2019, 13:46
    Do you have the packet baudrate set to 1200? sounds like you may have it set to 9600...
    3 replies | 130 view(s)
  • spbrhs07's Avatar
    Tue 15th Jan 2019, 08:23
    I am working on a weather balloon project and I'm trying to figure out my GPS transmitter. I'm using a Radiometrix HX1 radio module with an Arduino Uno 9v, 1A power supply. At this point it's all plugged into a breadboard as I'm still testing everything. For the antenna I'm using a 1/2 wave monopole whip. The antenna is connected to an SMA connector soldered to a PCB with soldered jumper wires going to the antenna pins on the HX1. Here is a picture of what I've put together, minus the temperature sensors and the buzzer... https://cdn.sparkfun.com/assets/learn_tutorials/7/8/1/trackuino_fritzing1.png If anyone's curious about the code, it can be found here... https://github.com/sparkfun/SparkFun_Trackuino Everything complies and uploads fine to the Arduino. The GPS locks to multiple satellites and it appears to transmit fine.
    3 replies | 130 view(s)
  • brandon lind's Avatar
    Tue 15th Jan 2019, 07:37
    brandon lind replied to a thread Base Radios IC-745 No RF output in Icom
    I am very confused... Let’s start with the known facts. You measured 8.04v at the + side of C21 (which also happens to be directly connected to the higher side of R29). You measured 7.61v between R29 and R3. This gives a voltage drop across R29 of 0.43v. Using ohms law, we can determine the current through R29 as being (.43/10ohm) = 43mA. The manual calls for 0.4v at the emitter of Q1 (you measured 0.180v). Since the emitter resistor is 2.2ohm, we should expect an emitter current of 0.4/2.2 = 182mA. Given a beta of 144 (you measured), there should be a current of 182mA/144 = 1.264mA at the base. Generally, a voltage divider type bias for a class A amplifier is designed to have at least 10X the current through it to stabilize the voltage at the base. Being the voltage divider is comprised of R3 and R2, and knowing R3 has the same current flow as R29, we know we are well within spec at 43mA for the divider circuit. Knowing we have 3.4X more than the suggested current through the divider (R3 and R2), it...
    14 replies | 558 view(s)
  • Dale Paul's Avatar
    Tue 15th Jan 2019, 01:59
    Dale Paul replied to a thread Base Radios IC-745 No RF output in Icom
    Brandon. I’ve ohmed R20, I don’t have a precision ohm meter so the reading I got was 0.1 ohm. The svc manual IDs it at 0.012 ohm and 5 watts. All transistors were replaced with OEM Mitsubishi parts, and matched pairs for the drivers and PAs. I checked Beta for each transistor before installing them and they were all good. Using my transistor tester I find the Hfe/Beta Q1 is 144, Q2 is 72, Q3 is 78, Q4 is 83, Q5 is 82. After I replaced Q1 (for the 3rd time) I ohm checked all transistor leads for good solder connection. I removed R23/R27 and ohmed them also, R23 was 435 ohms and R27 was 90.5 ohms. As I said earlier Q1 has been replaced twice before in trying to fix this problem. I have 7.61Vdc between R29 and R3, 180mV at the Q1 emitter when the mike is keyed. With an amp meter in series with W35 and W10 and the mike keyed, I get 3mA and adjusting R23/R27 show no increase or decrease.
    14 replies | 558 view(s)
  • Teslas_Understudy's Avatar
    Mon 14th Jan 2019, 23:27
    Hello everyone, I am joining in an effort to learn about amateur radio and hopefully get the basic license this year. Take care, and I look forward to doing lots of reading here! Sean.
    0 replies | 70 view(s)
  • mi5utc's Avatar
    Mon 14th Jan 2019, 22:42
    Came across this forum as I have similar problems with my TR9000 and was wondering if anyone had successfully resolved this matter ? I am wondering if the mode switch has something to do with it, maybe oxidisation creating a poor contact. Iíve had the PA replaced with a rare to find new one and radio puts out a very healthy 13w but the sudden drop in rf output still shows up from time to time. I flicked the mode switch about and the radio worked perfectly so Iím thinking a good clean if possible or a replacement if one could be found. I would take the switch out of curcuit in favour of permanent USB but I still dabble on FM. Any more advice or results out there ?
    6 replies | 8196 view(s)
  • doc_cj's Avatar
    Mon 14th Jan 2019, 15:36
    Hello all ... I am taking the Technician (and hopefully General) exams on Saturday, 01/19/19. So, as you can see, I am still a very new newbie, not only to this forum but to Ham Radio as an avocation. Here's just a bit about me to get me started on this forum. I'm in my sevent decade on this planet and recently retired. Over my career I spent 10+ years in law enforcement, 9 years as a private attorney, and then got into academia for an 18 year tenure run as a Professor. I hold the Juris Doctor (J.D.) and Doctor of Philosophy (Ph.D.) degrees. I am the author of a dozen books and more than thirty journal articles in academic (peer-reviewed) and professional journals. My interest in Ham goes back to the days when I was a kid and my Dad was into CB and eventualy Ham. This would have been in the early '70s. I used to spend many nights with him in his shack while he worked on repairing radios for friends and for a small fee. For some reason, though, I didn't get into the electronics aspect of the...
    0 replies | 51 view(s)
  • Richard Harries's Avatar
    Mon 14th Jan 2019, 11:20
    I've had a radio license for about 30 years but I haven't used it for a very long time, therefore I'm a bit ignorant about modern practice. I'll be rowing across the Atlantic in 2020 and I'm wondering if it is a practical option to use shortwave as a means of communication. I'd be very grateful if anyone with experience of using SW on an ocean could respond. Thank you.
    0 replies | 56 view(s)
  • paulears's Avatar
    Mon 14th Jan 2019, 10:27
    paulears replied to a thread Calculate Offset in Activity Forum
    The tyt th9000d we buy in the UK is TX/RX up to 174MHz. Is the US version limited to ham bands only? I'd also check that 168.495MHz frequency. 5KHz spacing is a new one for me on repeater splits - they're usually fairly big whole numbers - and if the TX ends in a '5' then the RX normally does too - 4.02Mhz is a very weird split even 4.025MHz, which is a 12.5KHz channelisation would be a bit strange - at least in the UK.
    4 replies | 156 view(s)
  • K7KBN's Avatar
    Mon 14th Jan 2019, 06:01
    K7KBN replied to a thread Calculate Offset in Activity Forum
    If you're required to use a radio as a condition of employment, the employer is generally required to furnish a legal, certificated radio to all such employees. The technician is absolutely right not to attempt to make a radio something it was never intended to be. What kind of radios do the other employees use?
    4 replies | 156 view(s)
  • brandon lind's Avatar
    Sun 13th Jan 2019, 22:01
    For the sake of the thread name.... you have your offset sign wrong. If the repeater TRANSMITS at 168, you RECEIVE on 168. That means you must transmit on 164, the repeater INPUT. Typically, radios denote offset direction from the receive frequency thus giving you a NEGATIVE offset, not +. As for whether or not that radio can TX out of the ham bands, no clue. i don't own one. I am in agreement with 5B4AJB regarding the likely necessity of a modification to make that happen. If you already modded it, make the offset -4.020 73!
    4 replies | 156 view(s)
  • 5B4AJB's Avatar
    Sun 13th Jan 2019, 20:38
    5B4AJB replied to a thread Calculate Offset in Activity Forum
    I two words - you can't. Unless you find a broadband transmit mod for the radio...
    4 replies | 156 view(s)
  • mess's Avatar
    Sun 13th Jan 2019, 17:24
    mess started a thread Calculate Offset in Activity Forum
    Hi guys, I'm new in here and would appreciate a little help or guidance. I have one of those tyt th9000d 2m radio. My issue is trying to figure the out the offset. Most repeater I have seen have a + or -600 for an offset but this one is for my work radio. The technician said he won't touch Chinese radios so I'm left with no radio. So correct me if I'm wrong, the repeater recieves on 164.475 and transmits on 168.495....I have the offset calculated to +4.020 . And the tone is 218.1 . Does any of this make sense? Thanks for any advise.
    4 replies | 156 view(s)
  • brandon lind's Avatar
    Sat 12th Jan 2019, 02:59
    brandon lind replied to a thread Base Radios IC-745 No RF output in Icom
    A closer look at the board confirms there would not be voltage on R20 with jumper W10 removed. I didn't realize R20 was AFTER the jumper as the schematic did not depict its location, no worries there. But ohm out R20 just for fun... Otherwise, those voltages look close but a bit low. Again, I am assuming the transistors you installed are identical replacements or suitable equivalents and are in working order AND installed correctly. The R23 and R27 pots, when adjusted, should give a current through the removed jumpers. Forgive me for asking, but are you making sure the ammeter is in DC mode and not AC mode and BOTH the probe tips each connect to where the W jumper ends were soldered in (using the ammeter as a jumper unlike a voltage measurement with the black probe to ground somewhere)? If done right, based on those measurements only 4 possibilities should remain: 1) the transistors have a much lower beta than the originals and the bias resistors need changing to different values, 2) the transistors...
    14 replies | 558 view(s)
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