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I have decided to include the SO-239 connector.
Pete "Michael A. Terrell" wrote in message ... starman wrote: Hi Pete, If you have to choose only one antenna impedance input, the high one would probably be more useful, particularly for users of real long wires like beverage antennas. However those like myself with an inverted-L which uses a matching transformer and coax lead would appreciate the 50-ohm input. Is there a reason why you are considering only a BNC connector for the low impedance input? How about a PC board mounted female F-connector which can be adapted by the users to their antenna lead wire. The "F" connectors are 75 ohm impedance. -- Former professional electron wrangler. Michael A. Terrell Central Florida |
Pete KE9OA wrote: The receiver will definitely have a high impedance input, and for the 50 ohm input, I will have a pad on the main PC board that the SO-239 connector center terminal can be soldered to. I wasn't too crazy about that BNC approach either. Hopefully, the receiver should hit the market by the end of summer. I will be leaving the company at the end of April, so I will get everything done that I can. I should have an initial board layout done in the next two weeks. What 'brand' will the radio have on it? dxAce Michigan USA Pete "starman" wrote in message ... Hi Pete, If you have to choose only one antenna impedance input, the high one would probably be more useful, particularly for users of real long wires like beverage antennas. However those like myself with an inverted-L which uses a matching transformer and coax lead would appreciate the 50-ohm input. Is there a reason why you are considering only a BNC connector for the low impedance input? How about a PC board mounted female F-connector which can be adapted by the users to their antenna lead wire. Any idea on when the MW receiver may hit the market? Pete KE9OA wrote: I am finishing up the MW receiver..............anyway, I have a high impedance antenna input in addition to the 50 ohm input. With this type of receiver is the high impedance input enough, or would interested parties rather have both inputs. The reason I am asking this is because my employer would like to have all jacks mounted to the main PC board. The only thing I have been able to find so far has been a right angle BNC connector for the 50 ohm input. Opinions welcomed! Pete ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Hi Eric,
I have decided to use an SO-239 for the low impedance input. For the high impedance input, I will be using a Mini-Circuits 4:1 transformer. The good thing about this approach is that the high impedance can come in at the transformer input while the low impedance can come in between either one of the balanced inputs and ground, the same way it is done in FM tuners. This way, the low-pass image reject filter doesn't get perturbed. This also eliminate the necessity of having an external matching device (believe me, I considered this avenue!). Pete "Eric F. Richards" wrote in message ... "Pete KE9OA" wrote: I am finishing up the MW receiver..............anyway, I have a high impedance antenna input in addition to the 50 ohm input. With this type of receiver is the high impedance input enough, or would interested parties rather have both inputs. The reason I am asking this is because my employer would like to have all jacks mounted to the main PC board. The only thing I have been able to find so far has been a right angle BNC connector for the 50 ohm input. Opinions welcomed! Pete, I'm in favor of the low-Z input myself. I wouldn't want to connect a "wire" to any receiver without some robust -- and sacrificial -- isolation. Would your boss be in favor of using (or recommending one of the existing) an external impedence matching device with binding posts on it? Pete Eric -- Eric F. Richards "Nature abhors a vacuum tube." -- Myron Glass, often attributed to J. R. Pierce, Bell Labs, c. 1940 |
I think you are correct Terry.............take a look at my prior responses.
This will illustrate the approach I have chosen. It should work out well. Pete wrote in message ups.com... Pete KE9OA wrote: I am finishing up the MW receiver..............anyway, I have a high impedance antenna input in addition to the 50 ohm input. With this type of receiver is the high impedance input enough, or would interested parties rather have both inputs. The reason I am asking this is because my employer would like to have all jacks mounted to the main PC board. The only thing I have been able to find so far has been a right angle BNC connector for the 50 ohm input. Opinions welcomed! Pete Add a switch to change the BNC from low-Z to high-Z. Include a BNC to dual banana adaptor. The slight notch in impedence shouldn't matter. And I would bet that any effect on reception could NOT be measured. Terry |
I am thinking that it will be either Silicon Engines or most likely,
Quadphase. This company has two divisions. Pete "dxAce" wrote in message ... Pete KE9OA wrote: The receiver will definitely have a high impedance input, and for the 50 ohm input, I will have a pad on the main PC board that the SO-239 connector center terminal can be soldered to. I wasn't too crazy about that BNC approach either. Hopefully, the receiver should hit the market by the end of summer. I will be leaving the company at the end of April, so I will get everything done that I can. I should have an initial board layout done in the next two weeks. What 'brand' will the radio have on it? dxAce Michigan USA Pete "starman" wrote in message ... Hi Pete, If you have to choose only one antenna impedance input, the high one would probably be more useful, particularly for users of real long wires like beverage antennas. However those like myself with an inverted-L which uses a matching transformer and coax lead would appreciate the 50-ohm input. Is there a reason why you are considering only a BNC connector for the low impedance input? How about a PC board mounted female F-connector which can be adapted by the users to their antenna lead wire. Any idea on when the MW receiver may hit the market? Pete KE9OA wrote: I am finishing up the MW receiver..............anyway, I have a high impedance antenna input in addition to the 50 ohm input. With this type of receiver is the high impedance input enough, or would interested parties rather have both inputs. The reason I am asking this is because my employer would like to have all jacks mounted to the main PC board. The only thing I have been able to find so far has been a right angle BNC connector for the 50 ohm input. Opinions welcomed! Pete ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Pete KE9OA wrote: I am thinking that it will be either Silicon Engines or most likely, Quadphase. This company has two divisions. Well, Silicon Engines does sound pretty neat. Pete "dxAce" wrote in message ... Pete KE9OA wrote: The receiver will definitely have a high impedance input, and for the 50 ohm input, I will have a pad on the main PC board that the SO-239 connector center terminal can be soldered to. I wasn't too crazy about that BNC approach either. Hopefully, the receiver should hit the market by the end of summer. I will be leaving the company at the end of April, so I will get everything done that I can. I should have an initial board layout done in the next two weeks. What 'brand' will the radio have on it? dxAce Michigan USA Pete "starman" wrote in message ... Hi Pete, If you have to choose only one antenna impedance input, the high one would probably be more useful, particularly for users of real long wires like beverage antennas. However those like myself with an inverted-L which uses a matching transformer and coax lead would appreciate the 50-ohm input. Is there a reason why you are considering only a BNC connector for the low impedance input? How about a PC board mounted female F-connector which can be adapted by the users to their antenna lead wire. Any idea on when the MW receiver may hit the market? Pete KE9OA wrote: I am finishing up the MW receiver..............anyway, I have a high impedance antenna input in addition to the 50 ohm input. With this type of receiver is the high impedance input enough, or would interested parties rather have both inputs. The reason I am asking this is because my employer would like to have all jacks mounted to the main PC board. The only thing I have been able to find so far has been a right angle BNC connector for the 50 ohm input. Opinions welcomed! Pete ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Silicon Engines? That sounds good for a name for a Radio.
cuhulin |
From: "Pete KE9OA" Organization: AT&T Worldnet Newsgroups: rec.radio.shortwave Date: Wed, 06 Apr 2005 12:16:46 GMT Subject: High performance MW receiver I am thinking that it will be either Silicon Engines or most likely, Quadphase. This company has two divisions. Pete Doesn't Pamela Anderson have silicone engines? Sorry, the devil made me say it. Greg |
"Michael A. Terrell" wrote:
starman wrote: Hi Pete, If you have to choose only one antenna impedance input, the high one would probably be more useful, particularly for users of real long wires like beverage antennas. However those like myself with an inverted-L which uses a matching transformer and coax lead would appreciate the 50-ohm input. Is there a reason why you are considering only a BNC connector for the low impedance input? How about a PC board mounted female F-connector which can be adapted by the users to their antenna lead wire. The "F" connectors are 75 ohm impedance. Technically true for VHF and UHF but not that important for MW or HF reception. I use R6U coax (75-ohm) for my HF antenna lead. ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
"starman" wrote in message
... "Michael A. Terrell" wrote: The "F" connectors are 75 ohm impedance. Technically true for VHF and UHF but not that important for MW or HF reception. I use R6U coax (75-ohm) for my HF antenna lead. I agree - the supposed impedance mismatch is a non-issue at these frequencies, connectorised CATV cable is available everywhere and cheap. The SO-239 is overkill and you want to make sure it is solidly mounted because it can be easily over-torqued. I wish they had used an F connector on the DX-394 because the SO-239 on one of mine rotated and fractured the solder pad on the pcb. Tom |
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