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#11
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Sync detector Drake R8B Radios.
cuhulin |
#12
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#13
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David wrote:
On 15 Dec 2005 16:25:25 -0800, wrote: Yes, HF Guy and Telemon, you guys hit the nail on the head. The sync on the R8B is the best. Steve The SW2 has a good one too. The SW8 was the first Drake to have the SSB (selectable side-band) sync' detector which was later used on the SW2 and R8B. The DSB (double side-band) sync' on the original R8 did not stay locked as well as the 'B' version. I don't know about the R8-'A' DSB sync' since I never had that model. |
#14
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In my previous post,I had meant to add, www.devilfinder.com Sync
detector Drake R8B Radios I guess I had forgot to add instead of subtract. cuhulin |
#15
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In article ,
Telamon wrote: In article R_4of.4765$Kk7.1619@trndny05, HFguy wrote: The sync' detector on my R8B never growls during an extreme fade. It stays locked. It also does DSB in addition to LSB or USB. wrote: The 7030 sync is a bit more versitile that that on the R8B. You can even do DSB reception, or any mixture of LSB and USB. It's hard to explain unless you have used one. However, the Drake gives you more bang for the buck, especially with the weak dollar. We did the test during the day, which is pretty difficult for shortwave. The nice thing about the 7030 sync is it never growled during extreme fading. I see someone else wrote the above and responding to the comment that the 7030+ sync is more flexible than the Drake R8B is wrong. The Drake has selectable sideband sync and the 7030+ does not have this function. Both radios have sync and you can adjust the passband on both but only the Drake can sync to one sideband or the other. The result is the blocking is better on the Drake since you can move the passband and select the side band with the least interference. So, what's the acoustic difference between using 1) an image reject mixer and a broad IF filter and 2) using any sort of product detector and a narrower IF filter? A sideband is a sideband. If the unwanted sideband is xx dB down from the desired signal, does it matter how it's done? Mark Zenier Googleproofaddress(account:mzenier provider:eskimo domain:com) |
#16
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Mark Zenier wrote:
In article , Telamon wrote: In article R_4of.4765$Kk7.1619@trndny05, HFguy wrote: The sync' detector on my R8B never growls during an extreme fade. It stays locked. It also does DSB in addition to LSB or USB. wrote: The 7030 sync is a bit more versitile that that on the R8B. You can even do DSB reception, or any mixture of LSB and USB. It's hard to explain unless you have used one. However, the Drake gives you more bang for the buck, especially with the weak dollar. We did the test during the day, which is pretty difficult for shortwave. The nice thing about the 7030 sync is it never growled during extreme fading. I see someone else wrote the above and responding to the comment that the 7030+ sync is more flexible than the Drake R8B is wrong. The Drake has selectable sideband sync and the 7030+ does not have this function. Both radios have sync and you can adjust the passband on both but only the Drake can sync to one sideband or the other. The result is the blocking is better on the Drake since you can move the passband and select the side band with the least interference. So, what's the acoustic difference between using 1) an image reject mixer and a broad IF filter and 2) using any sort of product detector and a narrower IF filter? A sideband is a sideband. If the unwanted sideband is xx dB down from the desired signal, does it matter how it's done? Mark Zenier Googleproofaddress(account:mzenier provider:eskimo domain:com) A good selectable sideband sync' detector uses phase cancellation of the opposite sideband which is more effective than just using a narrow filter and/or passband tuning. The audio is also better when you don't have to use a narrow filter. |
#17
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HF Guy - That makes sense. ~ RHF
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#19
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Kind of what I think too,narrow filter.
cuhulin |
#20
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In article ,
Telamon wrote: In article , (Mark Zenier) wrote: In article , Telamon wrote: In article R_4of.4765$Kk7.1619@trndny05, HFguy wrote: The sync' detector on my R8B never growls during an extreme fade. It stays locked. It also does DSB in addition to LSB or USB. wrote: The 7030 sync is a bit more versitile that that on the R8B. You can even do DSB reception, or any mixture of LSB and USB. It's hard to explain unless you have used one. However, the Drake gives you more bang for the buck, especially with the weak dollar. We did the test during the day, which is pretty difficult for shortwave. The nice thing about the 7030 sync is it never growled during extreme fading. I see someone else wrote the above and responding to the comment that the 7030+ sync is more flexible than the Drake R8B is wrong. The Drake has selectable sideband sync and the 7030+ does not have this function. Both radios have sync and you can adjust the passband on both but only the Drake can sync to one sideband or the other. The result is the blocking is better on the Drake since you can move the passband and select the side band with the least interference. So, what's the acoustic difference between using 1) an image reject mixer and a broad IF filter and 2) using any sort of product detector and a narrower IF filter? A sideband is a sideband. If the unwanted sideband is xx dB down from the desired signal, does it matter how it's done? The Drake blocks better because you can sync to the side band opposite interference and additionally you can move the bandpass control to that same sideband. The 7030+ demodulates and syncs to both sidebands and you can only move the passband control. But what happens when you set the 7030+ to a narrow bandwidth, to only cover the desired sideband? Does it sound better or worse than a R8[XYZ] set to a wider bandwidth and using the "I/Q"/"Phased"/"Image reject" mixer to cancel out the undesired sideband? As I understand it, an I/Q mixer typically is good for only about 40 dB of rejection. Is that better than the skirts on a good narrow filter? (I could have used another 40 dB this morning. The BBC at 16:30 on 7160 was getting stepped on by some other signal. Probably something in India on the greyline. So I used 3915 kHz, except that some of the local ragchewers were s9+30 about 10 kHz up, and the 6 kHz filter in my R-1000 couldn't cut it). Mark Zenier Googleproofaddress(account:mzenier provider:eskimo domain:com) |
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