Re: Topband: Single antenna port xcvr but want to employ separate receive antenna
Hi JC et al, just to add to the comments of JC: First of all it is a matter of switching timing. Always disconnect a separate RX antenna and short the rx entry to ground before the TX chain (with or without amp) starts to operate. Second: Get rid of any reradiation from the TX antenna which will otherwise destroy the the reception. Len SM7BIC -Ursprungligt meddelande- Från: Topband [mailto:topband-boun...@contesting.com] För JC N4IS Skickat: den 13 januari 2014 17:33 Till: 'James Rodenkirch'; 'Top Band Contesting' Ämne: Re: Topband: Single antenna port xcvr but want to employ separate receive antenna Hi James There are several solutions for a separated receive port. However let me comment on some details, 1- Small Delta loop. To be a receiver antenna the antenna gain need to be less than 20 db, why ? simple. Connect a power meter and a 50 ohms load on the Small Delta loop and measure how much power is captured from the TX antenna, I know several guy the burn the RX port on ICOM and YAESU radios using transmit antennas as receiver and injecting 100W into the RX port when transmitting with a legal limit amplifier. Port isolation and RF protection must be the first concern for any solution. If the antenna used for RX is resonant on the same TX band , you can really burn you RX front end. 2- Switch speed. The receive port need to switch fast than TX port. 20ms is not enough, most small frame relays switch around 20ms , To play safe it is necessary < 10 ms. Another thing to consider. 3- The RX antenna only will add some SN if it adds some directivity, otherwise the attenuator at -20db will do the same job. 4- Isolation, on low bands if you have s9+10db noise and only 50 db isolation between the RX and TX port, the signal from the TX antenna will be add to you RX signal degrading the signal to noise and reducing side and back nulls form the RX antenna. I can list another several reason to the subject but the T/R switch is a very important part of the receiver system if you want to have some improvement on the signal noise. I sent one RTR-1 to T6LG to use with a good Preamp from KD9SV and a Delta Flag antenna using twisted pair. Without the RTR-1 the system would not perform well as it did. Just my two cents. Regards JC N4IS -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of James Rodenkirch Sent: Monday, January 13, 2014 8:36 AM To: Top Band Contesting Subject: Topband: Single antenna port xcvr but want to employ separate receive antenna Have my vertical working great and have a small Delta-loop low band receive antenna BUT the Ten Tec Jupiter doesn't have a separate receive antenna like a K2, for instance (I borrowed a K2 to try out but the buttons/controls are to small for me to operate as I have a severe case of peripheral neuropathy, courtesy of Agent Orange).So, I am up and running and will be in the CQ 160 contest at the end of January but have no means, currently, of switching rapidly 'tween the top loaded vertical and loop. A T/R switch won't "do it" for meso looking at a DX Engineering RTR-1A but sure don't like the price!!http://www.dxengineering.com/parts/dxe-rtr-1a Anyone have an RTR-1 or 1A that is excess to their needs and willing to sell OR have another idea of how I can employ a separate receive antenna when I have one antenna port? Thank you, in advance, for any repliesoff line replies work for me. 72/73, Jim Rodenkirch K9JWV _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Single antenna port xcvr but want to employ separate receive antenna
I've used the loop and a KD9SV preamp with the vertical before, JC, and no overload problems ...I run QRP power during Top Band contests. Your cautionary notes are noted and appreciated! Jim R. K9JWV > From: n...@comcast.net > To: rodenkirch_...@msn.com; topband@contesting.com > Date: Mon, 13 Jan 2014 11:33:21 -0500 > Subject: Re: Topband: Single antenna port xcvr but want to employ > separate receive antenna > > Hi James > > There are several solutions for a separated receive port. However let me > comment on some details, > > 1- Small Delta loop. To be a receiver antenna the antenna gain need to be > less than 20 db, why ? simple. Connect a power meter and a 50 ohms load on > the Small Delta loop and measure how much power is captured from the TX > antenna, I know several guy the burn the RX port on ICOM and YAESU radios > using transmit antennas as receiver and injecting 100W into the RX port when > transmitting with a legal limit amplifier. Port isolation and RF protection > must be the first concern for any solution. If the antenna used for RX is > resonant on the same TX band , you can really burn you RX front end. > > 2- Switch speed. The receive port need to switch fast than TX port. 20ms is > not enough, most small frame relays switch around 20ms , To play safe it is > necessary < 10 ms. Another thing to consider. > > 3- The RX antenna only will add some SN if it adds some directivity, > otherwise the attenuator at -20db will do the same job. > > 4- Isolation, on low bands if you have s9+10db noise and only 50 db > isolation between the RX and TX port, the signal from the TX antenna will be > add to you RX signal degrading the signal to noise and reducing side and > back nulls form the RX antenna. > > I can list another several reason to the subject but the T/R switch is a > very important part of the receiver system if you want to have some > improvement on the signal noise. > I sent one RTR-1 to T6LG to use with a good Preamp from KD9SV and a Delta > Flag antenna using twisted pair. Without the RTR-1 the system would not > perform well as it did. > > Just my two cents. > > Regards > JC > N4IS > > -Original Message- > From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of James > Rodenkirch > Sent: Monday, January 13, 2014 8:36 AM > To: Top Band Contesting > Subject: Topband: Single antenna port xcvr but want to employ separate > receive antenna > > Have my vertical working great and have a small Delta-loop low band receive > antenna BUT the Ten Tec Jupiter doesn't have a separate receive antenna like > a K2, for instance (I borrowed a K2 to try out but the buttons/controls are > to small for me to operate as I have a severe case of peripheral neuropathy, > courtesy of Agent Orange).So, I am up and running and will be in the CQ 160 > contest at the end of January but have no means, currently, of switching > rapidly 'tween the top loaded vertical and loop. A T/R switch won't "do it" > for meso looking at a DX Engineering RTR-1A but sure don't like the > price!!http://www.dxengineering.com/parts/dxe-rtr-1a > Anyone have an RTR-1 or 1A that is excess to their needs and willing to sell > OR have another idea of how I can employ a separate receive antenna when I > have one antenna port? > Thank you, in advance, for any repliesoff line replies work for me. > 72/73, Jim Rodenkirch K9JWV > _ > Topband Reflector Archives - http://www.contesting.com/_topband > > _ > Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Single antenna port xcvr but want to employ separate receive antenna
Hi James There are several solutions for a separated receive port. However let me comment on some details, 1- Small Delta loop. To be a receiver antenna the antenna gain need to be less than 20 db, why ? simple. Connect a power meter and a 50 ohms load on the Small Delta loop and measure how much power is captured from the TX antenna, I know several guy the burn the RX port on ICOM and YAESU radios using transmit antennas as receiver and injecting 100W into the RX port when transmitting with a legal limit amplifier. Port isolation and RF protection must be the first concern for any solution. If the antenna used for RX is resonant on the same TX band , you can really burn you RX front end. 2- Switch speed. The receive port need to switch fast than TX port. 20ms is not enough, most small frame relays switch around 20ms , To play safe it is necessary < 10 ms. Another thing to consider. 3- The RX antenna only will add some SN if it adds some directivity, otherwise the attenuator at -20db will do the same job. 4- Isolation, on low bands if you have s9+10db noise and only 50 db isolation between the RX and TX port, the signal from the TX antenna will be add to you RX signal degrading the signal to noise and reducing side and back nulls form the RX antenna. I can list another several reason to the subject but the T/R switch is a very important part of the receiver system if you want to have some improvement on the signal noise. I sent one RTR-1 to T6LG to use with a good Preamp from KD9SV and a Delta Flag antenna using twisted pair. Without the RTR-1 the system would not perform well as it did. Just my two cents. Regards JC N4IS -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of James Rodenkirch Sent: Monday, January 13, 2014 8:36 AM To: Top Band Contesting Subject: Topband: Single antenna port xcvr but want to employ separate receive antenna Have my vertical working great and have a small Delta-loop low band receive antenna BUT the Ten Tec Jupiter doesn't have a separate receive antenna like a K2, for instance (I borrowed a K2 to try out but the buttons/controls are to small for me to operate as I have a severe case of peripheral neuropathy, courtesy of Agent Orange).So, I am up and running and will be in the CQ 160 contest at the end of January but have no means, currently, of switching rapidly 'tween the top loaded vertical and loop. A T/R switch won't "do it" for meso looking at a DX Engineering RTR-1A but sure don't like the price!!http://www.dxengineering.com/parts/dxe-rtr-1a Anyone have an RTR-1 or 1A that is excess to their needs and willing to sell OR have another idea of how I can employ a separate receive antenna when I have one antenna port? Thank you, in advance, for any repliesoff line replies work for me. 72/73, Jim Rodenkirch K9JWV _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Single antenna port xcvr but want to employ separate receive antenna
Ahhh...luv it when K.I.S.S. idea passes by, TimI can do that!! So simple, how come I didn't think that solution up!! Much appreciated! Jim R. K9JWV > From: tsho...@wmata.com > To: rodenkirch_...@msn.com; topband@contesting.com > Date: Mon, 13 Jan 2014 13:48:11 + > Subject: Re: Topband: Single antenna port xcvr but want to employ > separate receive antenna > > Traditionally a "T/R switch" means a switch to be used the other way, to > allow you to move a single antenna between your separate transmitter and > receiver. Ironic that here we are in the 21st century and some of use an > external box to do the reverse function! > > To switch between transmit and receive antennas on my rig, I use a small 12V > relay keyed via my Ten-Tec Eagle's "amp key" output when I'm on 160. > > Every transceiver made in the past 50 years has an amp key line of some kind. > On the Jupiter it's a phono jack labeled "EXT T/R". > > Tim N3QE > > -Original Message- > From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of James > Rodenkirch > Sent: Monday, January 13, 2014 8:36 AM > To: Top Band Contesting > Subject: Topband: Single antenna port xcvr but want to employ separate > receive antenna > > Have my vertical working great and have a small Delta-loop low band receive > antenna BUT the Ten Tec Jupiter doesn't have a separate receive antenna like > a K2, for instance (I borrowed a K2 to try out but the buttons/controls are > to small for me to operate as I have a severe case of peripheral neuropathy, > courtesy of Agent Orange).So, I am up and running and will be in the CQ 160 > contest at the end of January but have no means, currently, of switching > rapidly 'tween the top loaded vertical and loop. A T/R switch won't "do it" > for meso looking at a DX Engineering RTR-1A but sure don't like the > price!!http://www.dxengineering.com/parts/dxe-rtr-1a > Anyone have an RTR-1 or 1A that is excess to their needs and willing to sell > OR have another idea of how I can employ a separate receive antenna when I > have one antenna port? > Thank you, in advance, for any repliesoff line replies work for me. > 72/73, Jim Rodenkirch K9JWV > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ > Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Single antenna port xcvr but want to employ separate receive antenna
Traditionally a "T/R switch" means a switch to be used the other way, to allow you to move a single antenna between your separate transmitter and receiver. Ironic that here we are in the 21st century and some of use an external box to do the reverse function! To switch between transmit and receive antennas on my rig, I use a small 12V relay keyed via my Ten-Tec Eagle's "amp key" output when I'm on 160. Every transceiver made in the past 50 years has an amp key line of some kind. On the Jupiter it's a phono jack labeled "EXT T/R". Tim N3QE -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of James Rodenkirch Sent: Monday, January 13, 2014 8:36 AM To: Top Band Contesting Subject: Topband: Single antenna port xcvr but want to employ separate receive antenna Have my vertical working great and have a small Delta-loop low band receive antenna BUT the Ten Tec Jupiter doesn't have a separate receive antenna like a K2, for instance (I borrowed a K2 to try out but the buttons/controls are to small for me to operate as I have a severe case of peripheral neuropathy, courtesy of Agent Orange).So, I am up and running and will be in the CQ 160 contest at the end of January but have no means, currently, of switching rapidly 'tween the top loaded vertical and loop. A T/R switch won't "do it" for meso looking at a DX Engineering RTR-1A but sure don't like the price!!http://www.dxengineering.com/parts/dxe-rtr-1a Anyone have an RTR-1 or 1A that is excess to their needs and willing to sell OR have another idea of how I can employ a separate receive antenna when I have one antenna port? Thank you, in advance, for any repliesoff line replies work for me. 72/73, Jim Rodenkirch K9JWV _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Single antenna port xcvr but want to employ separate receive antenna
Have my vertical working great and have a small Delta-loop low band receive antenna BUT the Ten Tec Jupiter doesn't have a separate receive antenna like a K2, for instance (I borrowed a K2 to try out but the buttons/controls are to small for me to operate as I have a severe case of peripheral neuropathy, courtesy of Agent Orange).So, I am up and running and will be in the CQ 160 contest at the end of January but have no means, currently, of switching rapidly 'tween the top loaded vertical and loop. A T/R switch won't "do it" for meso looking at a DX Engineering RTR-1A but sure don't like the price!!http://www.dxengineering.com/parts/dxe-rtr-1a Anyone have an RTR-1 or 1A that is excess to their needs and willing to sell OR have another idea of how I can employ a separate receive antenna when I have one antenna port? Thank you, in advance, for any repliesoff line replies work for me. 72/73, Jim Rodenkirch K9JWV _ Topband Reflector Archives - http://www.contesting.com/_topband
