WB1GCM
| Joined: | Sat, Apr 4th 1998, 00:00 | Roles: | N/A | Moderates: | N/A |
Latest Topics
| Topic | Created | Posts | Views | Last Activity |
|---|---|---|---|---|
| Circuit Board Construction Question | Mar 23rd 2012, 13:10 | 4 | 1,476 | on 15/9/13 |
| 10 Meter AM | Nov 14th 2011, 19:24 | 4 | 1,761 | on 14/12/11 |
| Baofeng UV-3R Harmonic Fix | Nov 11th 2011, 14:18 | 1 | 1,614 | on 11/11/11 |
| Novice Trivia Question: 10 meters | Oct 26th 2011, 18:55 | 2 | 1,279 | on 1/11/11 |
| European AM'er Needs Help | Aug 25th 2011, 19:45 | 3 | 1,262 | on 23/11/11 |
| How to Set the Temperature Setting On a Soldering Station | Aug 16th 2011, 12:18 | 1 | 1,515 | on 16/8/11 |
| How to Remove Cigarette Smoke from a Newer Solid State Transceiver? | Aug 8th 2011, 18:15 | 5 | 2,703 | on 6/2/12 |
| Switching Open Wire Feedline Bewtween a Transmitter and Receiver? | Aug 8th 2011, 13:34 | 1 | 1,815 | on 8/8/11 |
Latest Posts
| Topic | Author | Posted On |
|---|---|---|
| Drake TR-4 "hum" when transmiting SSB | Howard60 | 3 weeks, 2 days ago |
| Howard, You may have a bad audio cable, which will cause hum in the audio. To check for this, press the PTT button and listen on another receiver with the RF gain turned down sufficiently. If hum is present, disconnect the microphone and key the PTT line with a jack and a clip lead (use caution, only do this with one hand behind your back). When keyed with no microphone, if the hum goes away, the microphone cord is defective, or possibly the microphone itself is bad. Try another microphone. Get another local ham to listen to your signal, if possible. The other cause of hum would be if your High Voltage filter (electrolytic) capacitors in the power supply are tired. Try sending in CW mode, with the key held down for a few seconds (use a dummy load so not to cause interference) and listen on another receiver. If the note is not pure and has a flutter or ripple to it, the HV capacitors need replacing. Or, your old Drake just doesn't know the words...... Bob Allison WB1GCM ARRL Test Engineer disconnect your microphone and see if you can manually key the PTT line. While keyed, listen on another receiver with the RF gain turned down sufficiently. |
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| Hi Fi AM | kc2ifr | 3 weeks, 6 days ago |
| Bill, There is no limit on bandwidth. One must use good engineering practices. That means, if the band is crowded, it's not exactly good engineering practices to take up a large portion of the radio dial. If it's the middle of the day and the (75M) band is quiet, then it can be fun to experiment a bit. When the band is crowded, it makes more sense to roll off the higher frequencies and concentrate the bandwidth for more effective communication. The best way to "see" the transmitted bandwidth is with a spectrum analyzer. It's a bit harder to determine the transmitted bandwidth by ear using a receiver only.. As far as the name calling goes, that's not good operating practice and it gives the wrong image of Amateur Radio in the eyes of non-Amateurs. It's fodder for commercial interests that we misuse the airwaves and our frequencies should go to the highest bidder. Bob |
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| RST (Readability, Strength, Tone) | KG6SYX | on 5/11/13 |
| You have an excellent question. You are correct; RST is based on the operator's judgement. The RST method of reporting received signals started long before there were signal strength meters on receivers. I have many very old receivers (ARC-5s, for example) that do not have an S meter. One could also be listening to a receiver with the AGC off (no S meter movement) and still give out an RST report. S-meter calibrations vary from manufacturer to manufacturer. I believe it was Collins Radio that came up with S9 = 50 micro-volts of received signal and I have observed that most manufacturers shoot for that reference mark, but do not always hit it. Bob Allison WB1GCM ARRL Test Engineer |
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| HTs with direct frequency entry | KD2ADL | on 3/9/13 |
| Yes. You need to be in the VFO mode, not the memory mode, to enter in frequencies directly with the key pad. All HTs I've used and tested have a VFO mode. Check the manual on how to do it. Some modern HTs have an "automatic offset mode", but you'll still have to manually enter in tone encoding (PL) if needed. 73, Bob Allison WB1GCM ARRL Test Engineer |
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| LoTW | K6VIB | on 3/9/13 |
| You are always welcome to write to the LoTW help desk at: lotw-help@arrl.org or call 860-594-0314. The staff is very friendly and patient, so please do not hesitate to contact the LoTW help staff directly. Bob Allison WB1GCM ARRL Test Engineer |
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