Great video Jim. Just wanted to add that some manual tuners do not have a "band" switch and instead have letters or numbers on the inductor. For my Dentron MT-2000 I set the two capacitors to their mid setting then turn the inductor switch until I hear the loudest signal. Then I transmit at low power and set the capacitors, starting with the left one (Transmitter matching) then the right one (Antenna matching) like you demonstrated in your video. The same process would apply to many of the MFJ manual tuners. 73, AD0QH
That does complicate the tuning. But, you can do it! Rotate the knob for the roller inductor first. Find a dip in the SWR. Tune the 2 capacitors several times for the minimum SWR and then retune the roller inductor. Two or three times should do get your tuner very close to the best match. Thanks for asking Russ. 73, Jim W6LG
Thanks for all your videos Jim! New to the hobby (testing on Friday the 19th!) and have enjoyed watching all your vids. Thanks for putting them out there.. :) Matt in Oregon (call sign to follow!)
Hi Jim! Just wanted to leave some feedback and say I really enjoy your videos. I'm somewhat of a newbie. I got my Tech license in '05 at 18, but life took over and I didn't use it too much. Luckily this year I renewed my license before the grace period was up, and am now studying for the General license. I'm excited to get on HF and am sure I will be referencing your videos! 73, KC9HNJ
Thanks. And, good luck on the license. I am going to be gone for a while. I am going to the UC Davis Med Center this morning and I may be in the hospital for a few days. I hope to do some new videos after I get out of the hospital. 73, Jim
Thanks for all your videos Jim! New to the hobby (testing on Friday the 19th!) and have enjoyed watching all your vids. Thanks for putting them out there.. :) mart in Oregon (call sign to follow!)
Thanks Matt. I am going to be gone for a while. I am going to the UC Davis Med Center this morning and I may be in the hospital for a few days. Good luck on Friday. 73, Jim
Hi... thanks for nice video Jim. I was using the building in tuner in the TS-590, it's tune fast but not getting full power out I wasn't really very happy with. Then I got Palstar AT2K it's much way batter especially with lower bands 40,80 and 160 with just only G5RV. I really prefer manual tuner.
Thanks Jim, Makes good sense and clear as always, I guess the next question is if you put a power/swr meter in line after the ATU will that show an accurate reading of how efficient or otherwise the antenna is at the non-resonant frequency? 73 Tom M6ONV.
Hi, That meter will not measure efficiency. It will just show SWR. SWR may or may not indicate resonance. Your question is very good and something that I need to cover. There is confusion about the meaning or value of SWR. Thanks for asking. 73, Jim
Hi Jim! My LDG auto tuner failed on me so I picked up a BW Model VS 300A manual tuner at the local swap meet for $50. Man, I love this thing! Tunes my long wire antenna on 10 through 80 no problem and I have had much better performance on those bands than ever before. I haven’t tried 160 because my wire isn’t cut for 160… but I will give it a try anyway. I won’t be surprised if it gets a match. Question for you- if I add another SWR meter between the tuner and the coax, will it read the same SWR as the SWR between my radio and tuner? If not, why not? Also, am I losing radiating power through the matching process?
Hi Jim, I plan to get into QRP in an apartment with an indoor antenna running 1 to 5 watts. Any suggestions? I've been looking at the MFJ pocket loop tuner and think that with a 0.625" exterior diameter copper tube (8' diameter) I should get about 66% efficiency. I realize the antenna is key to this kind of set up but unfortunately I'm stuck inside as far as antennas go. 73s
Hi, I don't recommend QRP for a beginner. Also, a loop requires retuning with frequency changes. You are going to be spending a lot of time tuning the antenna. Additionally, the feedline is very important. My guess is that with 5 watts from the transceiver you will be lucky to radiate 2 watts. For now, put up a 20 meter dipole that will be 100% efficient. Run 100 watts to the antenna. Use a low loss feedline so that you will have an ERP of 100 watts instead of 2 watts. If you are new, spending your time making contacts. 73, Jim
Hi, I don't know the answer. I am on the way to see another doctor today. I may have a chronic condition that is very serious. At this time I am not able to work. It is possible that I will not be able to work ever. Thanks for asking. 73, Jim
Hi Jim i have a quad band Mobile tyt9800plus ham radio that I will be using as a home base. It is a 10, 6, 2, & 70c . I will be using the diamond pre tune quad band cr8900a antenna with the tram 1465 nmo ground plane. I'm kind of confused on what good coaxe is the best one to buy with lo specification. Are any of these coax are compatible for this kind of radio with lo lost characteristics. The rg-8x vs the lmr 400 or the lmr 420 coax. I will using around 30 to 50ft. Of cable . I will be using all four band. Thanks ralph 73 kd5qww.
Hi, I don't operate on VHF or UHF. What you should do is look up either on a table or an online calculator, for UHF the loss for 100 feet and then compute half of that for your installation. RG8X is not low loss coax. I'll bet that when you look it up, you will find the loss to be about 2/3 of the power. In other words, you will put 20 watts into the coax and get 6 watts out the other end. I have not discussed the efficiency of that antenna system and groundplane. You might loose another 3 watts there. So for 20 watts from the transceiver you might radiate 3 watts. 73, Jim
Hey Jim, how about an off-topic question. Thursday morning, Rich, KI6UOV was talking about doing a fox hunt so I went home and built one of these; theleggios.net/wb2hol/projects/rdf/tape_bm.htm. It says it's 7.3 dBd gain. My question; is the gain for receive, transmit or both? On 146.500 it has a 1.1:1 SWR and 50 ohms impedance. In your words, "I'm amazed". Regards, Jeff, KK6CUG.
Hey Charlie "Fireguy 1322", When are we having lunch? Soon I hope. Great news on the antenna. That is such a smart design. I don't know what the gain would be. The 7.3dBd is higher than I would have guessed; but only by a little. In any case, the gain is the same for transmit and receive. As discussed in a prior video, we know that 6dB is 4 times. That's because each 3dB is a double or two times increase. Nine dB would be 2 x 2 x 2 which is about 8 times (there is a little rounding in my answer). So, we can estimate without a calculator that 7dB is about about 5 times. So, what does that mean? Well, your 5 watt handheld into a 7dB gain antenna is like 35 watts of Effective Radiated Power. A received signal that might be 50mV is about 350mV into the receiver. That is a huge advantage for finding that hidden transmitter with Richard. Also, that is why I have 2 yagis tied together on 20 meters. I have about 10 times gain. Thanks for asking Charlie. That was a very good question. 73, Jim W6LG
Hi Jim, thanks for your video. I think your technique is not the best. Tweak one cap for minimum SWR, then offset the other cap, even that makes the SWR worse. Then tweak the first cap again for minimum SWR. If the resultant SWR is worse, offset the second cap the other way, and tweak the first cap for minimum SWR. Keep repeating these iterations until the SWR is the minimum which you can achieve (Should be 1:1 if the load-impedance is within the capabilities of the tuner). It's a bit difficult to explain in words! But tweaking each cap in turn for minimum SWR will not necessarily result in the optimum settings. I think this is why often one hears complaints, about even expensive tuners, that "it will not get my SWR below 1.5:1" for example. My iterative technique above should get you to the unique settings, of the caps, for minimum SWR. I think your approach will not necessarily get you there; it will get you to a dip in reflected power, but not necessarily the best SWR. The same applies to adjustment of the output tank circuits in valve amplifiers; I often see people recommending your technique for that also; sad news for the valve possibly being unnecessarily stressed with that technique! Hope that helps! Vy. 73, Tim
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Great video Jim. Just wanted to add that some manual tuners do not have a "band" switch and instead have letters or numbers on the inductor. For my Dentron MT-2000 I set the two capacitors to their mid setting then turn the inductor switch until I hear the loudest signal. Then I transmit at low power and set the capacitors, starting with the left one (Transmitter matching) then the right one (Antenna matching) like you demonstrated in your video. The same process would apply to many of the MFJ manual tuners. 73, AD0QH
That does complicate the tuning. But, you can do it! Rotate the knob for the roller inductor first. Find a dip in the SWR. Tune the 2 capacitors several times for the minimum SWR and then retune the roller inductor. Two or three times should do get your tuner very close to the best match. Thanks for asking Russ. 73, Jim W6LG
Thanks for all your videos Jim! New to the hobby (testing on Friday the 19th!) and have enjoyed watching all your vids. Thanks for putting them out there.. :) Matt in Oregon (call sign to follow!)
Hi Jim! Just wanted to leave some feedback and say I really enjoy your videos. I'm somewhat of a newbie. I got my Tech license in '05 at 18, but life took over and I didn't use it too much. Luckily this year I renewed my license before the grace period was up, and am now studying for the General license. I'm excited to get on HF and am sure I will be referencing your videos!
73,
KC9HNJ
Thanks. And, good luck on the license. I am going to be gone for a while. I am going to the UC Davis Med Center this morning and I may be in the hospital for a few days. I hope to do some new videos after I get out of the hospital. 73, Jim
Thanks for all your videos Jim! New to the hobby (testing on Friday the 19th!) and have enjoyed watching all your vids. Thanks for putting them out there.. :) mart in Oregon (call sign to follow!)
Thanks Matt. I am going to be gone for a while. I am going to the UC Davis Med Center this morning and I may be in the hospital for a few days. Good luck on Friday. 73, Jim
Hi... thanks for nice video Jim. I was using the building in tuner in the TS-590, it's tune fast but not getting full power out I wasn't really very happy with. Then I got Palstar AT2K it's much way batter especially with lower bands 40,80 and 160 with just only G5RV. I really prefer manual tuner.
That Palstar is very good. I too prefer the manual type tuner. Nice to hear from you my friend. 73, Jim W6LG
that's nice, but what if you have a roller inductor instead of a tap coil?
Please see the answer to Russ Hilton. Your question is excellent. I should have covered that. 73, Jim W6LG
Thanks Jim, Makes good sense and clear as always, I guess the next question is if you put a power/swr meter in line after the ATU will that show an accurate reading of how efficient or otherwise the antenna is at the non-resonant frequency? 73 Tom M6ONV.
Hi,
That meter will not measure efficiency. It will just show SWR. SWR may or may not indicate resonance. Your question is very good and something that I need to cover. There is confusion about the meaning or value of SWR. Thanks for asking. 73, Jim
Jim . Can I trust my tuner if I bought it preowned . Does a Tuner need Calibration do see if it’s properly working ?
Hi Jim! My LDG auto tuner failed on me so I picked up a BW Model VS 300A manual tuner at the local swap meet for $50. Man, I love this thing! Tunes my long wire antenna on 10 through 80 no problem and I have had much better performance on those bands than ever before. I haven’t tried 160 because my wire isn’t cut for 160… but I will give it a try anyway. I won’t be surprised if it gets a match. Question for you- if I add another SWR meter between the tuner and the coax, will it read the same SWR as the SWR between my radio and tuner? If not, why not?
Also, am I losing radiating power through the matching process?
Hi Jim, I plan to get into QRP in an apartment with an indoor antenna running 1 to 5 watts. Any suggestions? I've been looking at the MFJ pocket loop tuner and think that with a 0.625" exterior diameter copper tube (8' diameter) I should get about 66% efficiency. I realize the antenna is key to this kind of set up but unfortunately I'm stuck inside as far as antennas go. 73s
Hi,
I don't recommend QRP for a beginner. Also, a loop requires retuning with frequency changes. You are going to be spending a lot of time tuning the antenna. Additionally, the feedline is very important. My guess is that with 5 watts from the transceiver you will be lucky to radiate 2 watts. For now, put up a 20 meter dipole that will be 100% efficient. Run 100 watts to the antenna. Use a low loss feedline so that you will have an ERP of 100 watts instead of 2 watts. If you are new, spending your time making contacts. 73, Jim
Hey Jim, do you know when your store might be open? I need some raincoat tape. Thanks.....I never miss a one of your videos....
Hi,
I don't know the answer. I am on the way to see another doctor today. I may have a chronic condition that is very serious. At this time I am not able to work. It is possible that I will not be able to work ever. Thanks for asking. 73, Jim
I'm so sorry...I will pray that you get good news....73, John
:(
Hi Jim i have a quad band Mobile tyt9800plus ham radio that I will be using as a home base. It is a 10, 6, 2, & 70c . I will be using the diamond pre tune quad band cr8900a antenna with the tram 1465 nmo ground plane. I'm kind of confused on what good coaxe is the best one to buy with lo specification. Are any of these coax are compatible for this kind of radio with lo lost characteristics. The rg-8x vs the lmr 400 or the lmr 420 coax. I will using around 30 to 50ft. Of cable . I will be using all four band. Thanks ralph 73 kd5qww.
Hi,
I don't operate on VHF or UHF. What you should do is look up either on a table or an online calculator, for UHF the loss for 100 feet and then compute half of that for your installation. RG8X is not low loss coax. I'll bet that when you look it up, you will find the loss to be about 2/3 of the power. In other words, you will put 20 watts into the coax and get 6 watts out the other end. I have not discussed the efficiency of that antenna system and groundplane. You might loose another 3 watts there. So for 20 watts from the transceiver you might radiate 3 watts. 73, Jim
Thanks Jim for response I will look in to this. Ralph kd5qww
I just looked. RG8X at 50 feet the loss is about 60%. LMR400 at 50 feet the loss is about 25%.
Hey Jim, how about an off-topic question. Thursday morning, Rich, KI6UOV was talking about doing a fox hunt so I went home and built one of these; theleggios.net/wb2hol/projects/rdf/tape_bm.htm. It says it's 7.3 dBd gain. My question; is the gain for receive, transmit or both? On 146.500 it has a 1.1:1 SWR and 50 ohms impedance. In your words, "I'm amazed". Regards, Jeff, KK6CUG.
Hey Charlie "Fireguy 1322", When are we having lunch? Soon I hope. Great news on the antenna. That is such a smart design. I don't know what the gain would be. The 7.3dBd is higher than I would have guessed; but only by a little. In any case, the gain is the same for transmit and receive. As discussed in a prior video, we know that 6dB is 4 times. That's because each 3dB is a double or two times increase. Nine dB would be 2 x 2 x 2 which is about 8 times (there is a little rounding in my answer). So, we can estimate without a calculator that 7dB is about about 5 times. So, what does that mean? Well, your 5 watt handheld into a 7dB gain antenna is like 35 watts of Effective Radiated Power. A received signal that might be 50mV is about 350mV into the receiver. That is a huge advantage for finding that hidden transmitter with Richard. Also, that is why I have 2 yagis tied together on 20 meters. I have about 10 times gain. Thanks for asking Charlie. That was a very good question. 73, Jim W6LG
Does my photo make me look like Charlie?
73, Jeff, KK6CUG
Sorry. My new glasses will be ready in a week. Struggling a little Jeff.
When we do go to lunch, I will buy!
You're on!
Just build a Fan dipole for the bands and you won't need a tuner.
A manual antenna tuner is a guy with a pair of side cutters....
Hi Jim, thanks for your video. I think your technique is not the best. Tweak one cap for minimum SWR, then offset the other cap, even that makes the SWR worse. Then tweak the first cap again for minimum SWR. If the resultant SWR is worse, offset the second cap the other way, and tweak the first cap for minimum SWR. Keep repeating these iterations until the SWR is the minimum which you can achieve (Should be 1:1 if the load-impedance is within the capabilities of the tuner). It's a bit difficult to explain in words! But tweaking each cap in turn for minimum SWR will not necessarily result in the optimum settings. I think this is why often one hears complaints, about even expensive tuners, that "it will not get my SWR below 1.5:1" for example. My iterative technique above should get you to the unique settings, of the caps, for minimum SWR. I think your approach will not necessarily get you there; it will get you to a dip in reflected power, but not necessarily the best SWR. The same applies to adjustment of the output tank circuits in valve amplifiers; I often see people recommending your technique for that also; sad news for the valve possibly being unnecessarily stressed with that technique! Hope that helps! Vy. 73, Tim