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dwmitchell61

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Everything posted by dwmitchell61

  1. I am curious as to how the heliax obviates any common mode current on the outer skin of the shield. Maybe I am misunderstanding the cause of common mode current on the feedlines? I thought it was due to imbalance in the antenna system. The PPT presentation you linked to above, on Page 6, states" "– Coax is not a part of these imbalances" So, I am wondering how your expensive heliax transmission line solves the issue. I have a lot to learn and don't know it all and am open to some mentoring from an "Elmer" It would seem that using ferrite beads of a proper mix rather than the old, trusty "ugly balun" method would be more effective at higher frequencies like GMRS. Thank you and 73 Dave, KJ7WUZ/WRHW845
  2. Ed Fong, PhD is an electronics engineer that is reputable and knows what he is doing. He developed these antennas from a request that he design an antenna given explicit criteria for a corporation in the communications business. There is no need to criticize unless you are willing to back your critique with explicit engineering facts. You don't have to buy Doctor Fong's products, but the proceeds do go to supporting the college students in his college courses. As for the big brand name antennas, I would suggest you take the time to look inside the next one you buy before you put it on your tower or mast. You might just be shocked by what you find, and maybe even a bit disappointed if you know anything about soldering and antenna theory. I intend to purchase his antennas for my use when I go portable. I just don't want to have to carry around some 10 foot to 17 foot fiberglassed fragile antenna that could be broken, then spend another $200-300 replacing it. Stay well, see you on the air, stay well and try to stay positive 73 Dave, KJ7WUZ/WRHW845
  3. I don't have an appropriate soldering station for the shielding. I tried to build a coaxial collinear antenna with a 25W iron on RG-8X and it was a mess. Even tried a butane soldering iron. If it's just the center pin, then that is manageable.
  4. This sounds like it may get expensive... Windstorm brought down mast & destroyed my base antenna. So's I buys a new antenna. The XYL says radios have to leave the bedroom, son has moved out, I now have a radio shack (and XYL used to manage Radio Shack here, LoL). Make a long story short. New mast, new antenna, new location, in the air, all guyed up, cables awaiting window feedthrough... I look over and find my Welsh terrier hanging from the GMRS coax and she's having a great time. I look and there are holes all the through the external insulation. Now I get reports I am "loud and clear but scratchy". Looks like I am going to lose some length in the cable... About how much is a crimper set for doing N-type connectors on LM-400? Maybe someone at the club will graciously let me borrow theirs?
  5. The words he speaks are true... I have a repeater 8 miles out on my HT ham radio. I can reach it using 1W loud and clear. My "base station" putting out 40W cannot reach a repeater 26 miles out, due to a mountain between us. I can, however, reach another about the same distance because there are no hills between us.
  6. On channel 1 I am receiving a constant beep. I thought I heard some family chat in the distant background. One of the neighborhood kids must have set his radio down with an emergency beacon or something turned on. No channel 1 until the battery runs down, I guess.
  7. Thanks folks. I found it before I found your messages. Sure appreciate your help, none the less.
  8. Oregon CIty 575 and Oregon City 575-2 repeaters are not showing in my searches. Repeater owner is WRAS495. I can however, searh by his call sign and pull them up. But the lack of visibility in the "NEAR ME" and "ADVANCED SEARCHES" is probably limiting the usage on his repeaters. Thank you, Dave, WHRW845
  9. Is there a way, to age repeater records so entries for repeaters that never made it online or have been taken down are removed from the database. There are like 4 or 5 repeaters listed in my area that have never responded to a transmission in the two years I have been here...., show no activity of the owner and which the owner does not respond when correspondence is sent to them about the repeater.
  10. If you are lucky, it is in the DC power to the radio, from the car. Get a big CAPACITOR from electronics supply house or auto stereo shop and connect it across the wires
  11. I did the antenna upgrade to my Wouxon KG-805..... A Nagoya antenna. Works alot better than antenna included in the purchase of the radio. Reaching people 4-5 miles out while in my easy chair. They used to say, "As much wire in the air, as high as possible." I have adapters for the SMA to a SO-238 so I can connect it to the Comet CA-712EFC base antenna.
  12. I guess you won't mind if I sit in the chair next to you at the doctors office and pass some gas, then? LMAO..... Sorry, poor analogy but it seemed funny at the moment...
  13. It's okay. From what I understand, rants are very much in vogue right now! LMAO...
  14. Huh.... I checked the radiator AFTER soldering it into the center pin on the connector... It is 3mm to long... See what happens tomorrow as I go through teh steps above.
  15. The MXT-400, if you buy the DBR1 cable and ask Midland support for the programming software download, has a few options that can be changed. 1) On power up, mine displays my call sign 2) I have the four local repeaters programmed into CH 8-11, they were empty due to unused FRS not permitted by FCC. 3) You can program display names into your channels. 4) Bandwidths that can be programmed into the channels are: 12.5kHz (narrow), 20kHz (medium) and 25kHz (wide). The factory had the repeater channels set for 25kHz on mine. 5) I can also program the repeater frequencies for which no repeaters are in use in my area for "talk-around" operation as a preset. The MXT400 isn't very versatile in programming from the front panel. I think I am going to try one of those Wouxon KG-1000G's. I'd like to try one of those old rigs, Kenwood or Motorola, if I can get the software legally and it is 95A certified. I have a deep respect for Motorola products, but I don't want any risks in getting on the FCC's bad side. I get a ticket EVERY time I do more than 5mph over the speed limit... It's like they're just waiting for me to make a misstep!
  16. Unhook the antenna cable, DO NOT TRANSMIT! But listen under same conditions with antenna cable unhooked... Still there? Put one of those BIG capacitors across the power wires as close to the radio as possible. I think they do that for those BOOM-BOOM amps the kids put in their Hondas.
  17. If only the US offices based here selling the Chinese, Singaporean and Malaysian radios would just bring the manufacturing back to the US.... SMH.... I know everyone says use a Part 90 reprogrammed... Plentiful and low priced used units. I would love to. But at my age, with cancer, a year in jail for doing so is just too expensive, and with my medical conditions having a $10,000 fine would be impossible for me to pay... So I just bought a Part 95A/E unit. I am the guy that gets a ticket EVERY time I do 5mph over the speed limit. So I live with the FCC rules and buy an overpriced CCR radio. They seem to do okay for me. My ears don't hear too well either, so intermodulation hasn't been detected by them and "hi-fi" wideband FM is a waste with my hearing. I have a Wouxon KG-805G handheld and the Midland MXT400.... I am tempted to get a couple of these CCR's and a duplexer just to see how well it works. I know for some, it is like a religion and they are very devout, something like the whole Chevy/Ford debate in the auto discussion groups, it is getting like the whole left/right political environment... Everyone just seems so passionate and devoted to a singular view with a closed mind approach. It actually makes me want to duck out of here. SO.... I think I will just talk about my home brew antennas... They are made in the USA... LoL
  18. I made a home brew antenna today. I built a 1/4-wave ground plane with 6 ground plane elements today. The SWR is a tad high at the higher repeater channels/frequencies (467MHz). The 462MHz channels/frequencies run a low SWR. I will try making the angle on the ground plane elements a bit steeper first. Then I will try trimming the element lengths, bit by bit. This will be one of my "go box" antennas. I may try a commercial made antenna with a ground plane kit I bought from here. I broke one of the ground plane elements, so will replace them with 12AWG copper wire. The quagi long-beam I built to use for reaching a distant repeater had very high SWR. It was scaled from a 440MHz antenna design. I need to rework the quad loops on it to match it. Another project I want to build is a cubical quad "go box" antenna. So many projects, so little time... Trying to fix up our home to sell at the same time.
  19. I was just wondering if you actually went through the menus. The MXT400 has a menu option to turn off the transmit function, thereby making the unit a receiver.
  20. It should.... And will have NOAA channels as I understand. My MXT400 came from the factory with the repeater channels set to 25kHz (wideband), contrary to the rumors circulated by those with a bias against Midland radios that it does not support wideband. It is simply amazing that those who do not own one make all these claims as though they are the "gurus" chanting the mantra from the mountain top upon which they seated themselves. It will also do 20kHz if you like. It can also be software programmed to do split tones, CTSS and DCS even, on same channel. You must buy the DBR1 cable from Midland and they give you a limited-life link to the software download when you call them. I programmed mine to display my call sign on startup All my simplex channels are programmed as wideband (25kHz). . I programmed the four local repeaters into the empty channel slots that were empty for the 0.5W FRS channels, displaying the repeater names OR CITY, TABOR, OVRLOOK and GRESHAM when they are chosen. Someone also said programming the radio invalidates the certification. Midland denies this. The radio was certified under Part 95A and as such, is grandfathered under the new parameters specified under Part 95E. As long as the radio is still operating within the Part 95E specifications when programmed, you are fine. It does what I want., and I am satisfied with my purchase. It doesn't have 10 billion "bells and whistles" to clutter up the menus and programming like some other radios. It doesn't have FM, but my car and my Sangean WR-11 and ATS-909 take care of that.
  21. Maybe we should go back to tube units manufactured before the FCC came into existence? I was looking at the Kenwood TK-880 and Motorola CM-300 and the labels state they are made in Singapore and Malaysia, respectively... Can we add CSR and CMR to the "cheap" list? Buying E-Bay goods is risky at best... What mods have been done? Are the finals fried? I just bought a used RS HTX-202 (Icom design) and it doesn't receive/transmit..... I did get my money ($10) worth in the accessories that came with it for the other working unit I have. Caveat Emptor....
  22. One word.... FIGURES! LoL... Probably change for the worse in the next ten years. BTW, studying for my Tech exam, and I guess they are going to charge fees for licensing in the amateur arena... Ugh!
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