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  • Tempstar's Avatar
    Sun 28th Feb 2021, 14:10
    What wiring is connected to the desk? I don't see where a typical metal desk could build a charge as it would be a very poorly constructed capacitor. If the desk is not connected to a ground then the 5.44 volts you are seeing is likely hysteresis in your meter. A sure test would be to ground the desk temporarily to the electrical ground and see if the problem persists.
    7 replies | 460 view(s)
  • brandon lind's Avatar
    Sat 27th Feb 2021, 08:38
    no current on the ground wires at the box. Used a Klein Tools CL390 clamp on to check.
    7 replies | 460 view(s)
  • Tempstar's Avatar
    Fri 26th Feb 2021, 13:45
    Someone has bonded neutral and ground together somewhere. At the main breaker box check for amperage on the ground. From there you have to work backwards to find where your ground is being used as a current carrying conductor. It's never a good idea to bond metal objects at a transmitter site to building electrical ground, but rather give them their own conductor to an outdoors earth ground.
    7 replies | 460 view(s)
  • Tempstar's Avatar
    Fri 26th Feb 2021, 13:32
    Tempstar replied to a thread DCSCO in Introduce yourself
    DCSCO, be sure and check out the NC PRN network. It's DMR that covers NC,SC, parts of VA and WV. I look forward to hearing you on the air from SC!
    2 replies | 480 view(s)
  • Dale Paul's Avatar
    Wed 24th Feb 2021, 14:54
    Brandon. Thank you again. I have profound hearing loss and have to use special devices to listen to my radios. Certain letters of the alphabet all sound a like. Again, thank you. Dale
    2 replies | 276 view(s)
  • brandon lind's Avatar
    Tue 23rd Feb 2021, 18:17
    End-Fed? People like to drive long wires from the end with a 49:1 or similar balun (to match the high impedance found at the end).
    2 replies | 276 view(s)
  • Dale Paul's Avatar
    Tue 23rd Feb 2021, 16:29
    I hear a lot of talk about the NSED/NSAID(sp) antenna and I'm not sure how to spell it to look on the internet for information about it. Can some one shed some light on it for me? Thanx.:chargrined:
    2 replies | 276 view(s)
  • gnuuser's Avatar
    Sun 21st Feb 2021, 23:20
    gnuuser replied to a thread DCSCO in Introduce yourself
    greetings Dave I havent been able to get my ticket yet due to covid restrictions. but that does not stop me from learning or building.
    2 replies | 480 view(s)
  • gnuuser's Avatar
    Sun 21st Feb 2021, 23:13
    dont discount technician license and even though its not required for the license learn morse code for cw communications, purchase some qrp radio kits and build them. they are a valuable tool for learning. and it opens up a lot of bandwidth to you. learn how to make and build your own antennas Talk to us and other ham operators we are happy to help If you are interested in qrp kit radios Ill post a few links for you.
    4 replies | 675 view(s)
  • 2E0JTP's Avatar
    Sun 21st Feb 2021, 13:18
    How's that Technician licence coming along?
    4 replies | 675 view(s)
  • DavidJ's Avatar
    Sat 20th Feb 2021, 22:41
    Thank you for the comment!
    4 replies | 675 view(s)
  • KD9KVS's Avatar
    Sat 20th Feb 2021, 13:59
    I like that a lot!! I used the frequency counter on the front end getting the frequency for the mics. Since the antenna for the mics are omnidirectional I took a general reading of the area. The bandwidth of wireless mics are much more wide than what I had expected! I guess that’s why they have a great signal and very little in the way of dropping signals. I think I will try and build one like what you have there to have more than one option for this type of thing.
    3 replies | 337 view(s)
  • 5B4AJB's Avatar
    Sat 20th Feb 2021, 11:58
    I had a similar problem once, I used a simple crystal style radio with a sensitive meter on the output, biased with a battery. Basically a powered field strength meter. Will have a rummage round and try to find the (extremely simple) circuit diagram, I still have the meter working daily to tell me about any local transmissions, lightning etc. Going around touching the antenna probe on various metalwork eventually showed me the problem. Having a gain control is very useful for this! You could go a step further and have a cheap frequency counter module (see ebay) to pinpoint the exact frequency, but interference is interference... I tried to reverse-engineer it, but my eye's aren't what they used to be, maybe you can have a go... parts list, best I can tell diode - OA81
    3 replies | 337 view(s)
  • brandon lind's Avatar
    Sat 20th Feb 2021, 01:15
    No blown bulbs or brownouts. Good suggestions though. Thanks! I am going to take the clamp-on to the ground wires coming into the panel. I took the cover off yesterday but haven't had a chance to check. I have a whole week of being stranded in the middle of nowhere (introverted vacation!) waiting on rockauto to bring a wheel bearing so I'll have some spare time on my hands to dig into this further.
    7 replies | 460 view(s)
  • brandon lind's Avatar
    Sat 20th Feb 2021, 01:01
    If you have access to a spectrum analyzer, you can see what areas on the spectrum are hot in the bad area and not so bad in the location you found to work better. Outside signals will, for the most part, remain at a constant level throughout a building, give or take a few dB. Once you identify the offending signal by its larger dB change around the building, you can have someone turn off breakers one at a time to see what circuit the offending device is on. Then narrow it down by pulling power cords. A higher noise floor at the intended frequency can be caused by much lower frequencies with harmonics, often something in the kHz range. If there is a 120Hz hum to the static, it is likely 60Hz grid related. If the noise is more white sounding, its likely a switch mode power supply somewhere (maybe a laptop charger). If you can take a look at 1kHz through about 100kHz while cutting the power to things, you might find the cause. EDIT: most SDR's cant go that low but still show "noise". This noise is from the...
    3 replies | 337 view(s)
  • KD9KVS's Avatar
    Fri 19th Feb 2021, 21:23
    Looking through posts I am seeing a lot of questions about interference and how to find the source. I’ll start with a story... At our church we were having issues with volume levels on our recording and livestream. If the volume was low, preventing an air static noise, people could not here spoken words well. If the volume was up, there was the air/static noise and they did not like that. So I went through, checking grounds, making sure the power conditioners were operating properly, making sure there were no issues with amplifier oscillators causing an issue... all of which could very easily cause the issue. None of the above were causing any sort of problem. I decided to break out the ham gear and see if radio interference could possibly be the problem. Using a frequency counter, I found the transmit frequency of the wireless mics. Next I hooked up the S.D.R. And went to the frequency on the frequency counter with the mic transmitting. After turning the mic off, I saw 16db of radio activity in that...
    3 replies | 337 view(s)
  • gnuuser's Avatar
    Fri 19th Feb 2021, 04:03
    run a bonding strap to the ground conductor to bleed off induced voltage and current. a metal desk can induce voltage by acting as an antenna with a fluctuating magnetic field present in most house wiring applications. (depending on the load usage). one good indicator of a loose or bad neutral is it tends to blow incandescent lamps when switching on. (upstream of the bad joint) downstream of a bad neutral between hot and neutral will be no current flow! hot to ground Yes there will be current flow. first place to look for loose or bad grounds ( if not in the junction boxes) is the neutral and ground buss bars in the breaker/ fuse box. make sure the screws are all tight. another indicator is intermittent surge and brownout during a temperature change it means a bit of running back and forth but eliminate the outside ends and work your way inward on the circuits until you find the culprit( bad or loose connection)
    7 replies | 460 view(s)
  • brandon lind's Avatar
    Wed 17th Feb 2021, 18:07
    I would have to tear the wall apart to do that. I have not built any transformers.
    7 replies | 460 view(s)
  • 5B4AJB's Avatar
    Wed 17th Feb 2021, 11:27
    You have built a transformer? Check your mains cabling is not running parallel to the metalwork! I had a similar problem, run a metal tube over the last few feet of mains, isolated, floating...
    7 replies | 460 view(s)
  • brandon lind's Avatar
    Wed 17th Feb 2021, 01:12
    I have a mystery. Between ground and my metal desk (I thought I had grounded) there exists 5.44V of 60Hz AC. I have unplugged everything on the desk and from mains ground to my desk there is still roughly 5.44v between the two. My voltmeter has a very high impedance so it is possible that the desk is able to couple power into the air or what is going on? I'm wondering if I have current in my ground wiring from a bad neutral somewhere else in the house...
    7 replies | 460 view(s)
  • brandon lind's Avatar
    Tue 16th Feb 2021, 20:51
    I wanted to compare the nanoVNA-F to the Siglent SVA1032x so I calibrated them both with the same kit and took screenshots of the 75ohm yagi I made for ch12 OTA TV (207MHz) through about 50' of 75ohm coax (VNA's calibrated to 50ohm). I was surprised how well the nano did in comparison. The reactance was almost identical between the two, but the resistance was a few ohms higher on the nano. I was originally frustrated with the nanoVNA because it gave me horrible readings and consistently failed gamma match adjustments, but now that I updated the firmware (again) on the nano, I must admit, it isn't too bad. I've done 3 firmware updates now in a month or so and I finally found one that works the way I want it to. I'll be comparing the two units at 70cm soon. I also noticed that just about every antenna I connect to, there exists enough common-mode current to significantly change the impedance readings just by touching or approaching the coax which gives me a new appreciation for baluns! I highly recommend a...
    0 replies | 237 view(s)
  • KD9KVS's Avatar
    Sun 14th Feb 2021, 19:05
    Chances are it works fine. One thing to keep in mind is to make sure your ctcss dcs is set to off so that you can receive all signals transmitted on the frequency. The repeater will only come live when someone is transmitting on it. If you want a little more selectivity, turn the tones on and make sure that it is set to the correct one. At that point in time your squelch will only open (allow you to hear transmissions ) when that tone is heard. Squelch is another thing to keep in mind. If it is set to high, it takes a very strong signal to open it and you may miss what is going on. If it is to low, every power line can cause it to open, or constant static. Just a couple things to check.
    4 replies | 441 view(s)
  • Higgins420's Avatar
    Fri 12th Feb 2021, 14:31
    whey thats brilliant thankyou i will keep an ear on the local repeaters :) is there somthing to be heard on them constantly or is it only when someone is transmitting through them ? im starting to wonder weather my radio works or not haha
    4 replies | 441 view(s)
  • 2E0JTP's Avatar
    Thu 11th Feb 2021, 22:09
    Monitor 145.500 (the 2m calling frequency) and the local 2m/70cm repeaters. That's a good place to start. Find out if you have any local radio clubs, and if they have any weekly 2m/70cm nets.
    4 replies | 441 view(s)
  • 5B4AJB's Avatar
    Thu 11th Feb 2021, 15:03
    You might have to go to the top of a hill to pick up some repeaters, but you should be able to hear/work several even on a small antenna. This repeater coverage map, might help...
    4 replies | 441 view(s)
  • Higgins420's Avatar
    Thu 11th Feb 2021, 12:11
    hi, i have just bought my first radio (Baofeng UV5R) and was wondering how hard is it to find a sinal on 2m/70cm? i live in a village in dorset that does have next to no radio reception, its in a dip and the signal on the radio in the car cuts off as soon as you drive into the village. ive made a dipole for 2m and another for 70cm that actully picks up FM commercial radio very clearly, but when i scan through either band i dont pick up anything. how likly is it that somone will be transmitting on VHF/UHF within range of me? do you usually have to go hunting for signals in a rural area or should i be picking somthing up ? i did go for a walk up the nearest hill and still nothing, at most it will stop on a frequency and make some interference noice for a minute then move on :/
    4 replies | 441 view(s)
  • WZ7U's Avatar
    Thu 11th Feb 2021, 05:56
    WZ7U replied to a thread Emergency frequencies in Amateur Radios
    https://www.radioreference.com/apps/db/
    3 replies | 1116 view(s)
  • gnuuser's Avatar
    Tue 9th Feb 2021, 03:11
    you can program the radios to monitor the frequencies but even with a license you cannot use a ham radio to transmit on those frequencies doing so can get your license revoked!
    3 replies | 1116 view(s)
  • gnuuser's Avatar
    Tue 9th Feb 2021, 03:05
    gnuuser replied to a thread ground rods in Amateur Radios
    we used a small jackhammer works very quickly! ground rods or rebar either one (funny story on that) at my last job they had a couple big fellows hammering rebar into the ground and they were having a rough time. we had a small jackhammer where we were removing a set of concrete steps. so i told them just hold a bar upright and stood up in the back of the truck and set the jack hammer on the rod, 5 seconds for a 10 foot rebar. didn't have to pay for any beer that night:glee:
    17 replies | 2633 view(s)
  • DCSCO's Avatar
    Sat 6th Feb 2021, 22:57
    DCSCO started a thread DCSCO in Introduce yourself
    CQ CQ. I’ve been licensed for about 10 years. Recently passed the general exam. I listen to 2m around the north Greensboro , North Carolina area. Studying for the extra when the Covid hit. I expect to expand my horizons in the radio world to digital and dx. Dave KB3TVE
    2 replies | 480 view(s)
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