ralphm
| Joined: | Fri, Jul 15th 2016, 22:48 | Roles: | N/A | Moderates: | N/A |
Latest Topics
| Topic | Created | Posts | Views | Last Activity |
|---|---|---|---|---|
| Understanding SWR | Jun 12th 2017, 21:14 | 4 | 7,806 | on 29/8/19 |
| Ham Radio's High Horse | Jun 12th 2017, 20:12 | 4 | 7,058 | on 29/1/18 |
Latest Posts
| Topic | Author | Posted On |
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| Ham Radio's High Horse | ralphm | on 12/10/17 |
| I'll bet FirstNet was not useful in Puerto Rico, but Amateur Radio was! Pretty tough to top mobile or portable HF with a battery and a solar panel. | ||
| Ham Radio's High Horse | ralphm | on 25/6/17 |
| Thanks for putting my comments into a clearer perspective. I think you make a very good point regarding FirstNet. Ralph VE7DQS |
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| Understanding SWR | ralphm | on 12/6/17 |
| For those who are constantly wondering about SWR, I invite you to read an excellent article written by K5DVW on the topic from the November 2006 issue of QST. It was an "eye opener" for me. |
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| how can you measure the rx noise floor at your qth | km5bor | on 12/6/17 |
| To put this noise floor stuff into perspective, -140dBm in a 50 ohm system is 0.022uV. I think even the best receivers have a sensitivity of about 0.25uV for 10dB S+N/N for < 2kHz bandwidth. RF amps, mixers, and IF amps and detector all add noise. | ||
| Ham Radio's High Horse | ralphm | on 12/6/17 |
| I know that some of what I write here will raise the hackles with some members, while others may agree and some may not care, but I feel this topic needs a visit once in a while. We "ham operators" have an obligation to be cooperative with all our neighbours, both on and off the air. Amateur Radio isn't just about putting up a big antenna with a high tower, or running 1kW linear to make QSOs a 1,000 miles away. There are many other interesting aspects of this hobby which can be happily pursued even by the veteran operator, like working QPR or (re)learning CW. Those alternatives might put some fun and mystery back into the hobby for many. Hams need to be good ambassadors to the hobby, and should practice empathy towards their neighbours. When a compliant arises, try a conciliatory approach first; you’ll find that it pays dividends. If you annoy your neighbours without regard, you’re going to find it a pretty lonely place to live, and you’ll see these people on a daily basis. Not a nice scenario. If your neighbours protest about your plans to erect a high antenna tower, then why not consider alternatives, like a Zepp, inverted-V, or end-fed long wire? If they complain to you about RFI, then remember, 6dB is only 1 S-unit, and it’s not the end of the world to give up some ERP. Most readers will know that 100W on a fairly modest antenna still goes a long way. If you’re booming in at the other end of the conversation at 20dB/S9, then reduce your transmit power by factor of ten and still enjoy a solid QSO, well above the noise floor. And, there might be another operator trying to use the same frequency and he can hear you, but you may not be able to hear him. Finally, the old argument that ham operators will “save the day” during times of natural disaster may have been true 20 years ago, but I think that “ship has sailed” with the advent of many more cellular sites and more citizens now owning satellite phones. Some of us may need to get off that high horse and recall that our pursuit is a privileged hobby not an essential service to the community. |
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