Re: Topband: TX/ RX Antenna Switching
If something goes wrong in the RX antenna switch, you don't have to worry about the rig transmitting into its own receiver. That can't happen. The only thing that can happen is that you could damage the antenna or its preamp. The reed relay is just like the one in your radio, so it shouldn't be unreliable. I've never heard of one of those failing. Reed relays, and on rare occasions other relays or relay systems, come in two variations. Some use a single contact bar that moves between NO and NC positions. These are OK, because they can never do two connections at once if something fails. The contact carrier is either one way or the other. These are potentially good as transfer relays. Some use dual reeds or dual contact carriers that are mechanically independent. If something goes wrong, they can make two connections at the same time. They also can have sequence issues where they make two connections at once. Some vacuum reed relays have two glass tubes inside the coil with independent NC and NO reeds. These relays are questionable for anything. They can lock in two contact positions at once, tying all three terminals of a DPST together. As a matter of fact, they actually do this for a millisecond or so when transferring. These are bad relays for many applications. By the way, some popular radios transmit RF even after telling the external relay line to release, and some transmit at the very same time as they tell an external relay to transfer. Most radios are good, but not all radios are good at timing. Some hot switch on the leading edge, and some on the tailing edge. 73 Tom ___ Topband reflector - topband@contesting.com
Re: Topband: TX/ RX Antenna Switching
Forgot the link to Array Solutions RF Limiter / Front Load Protector (Helps to know what they call these items so you can search for them :-) i.e.. Front End Protector. http://arraysolutions.com/Products/as_rxfep.htm That's a terrible protection system. It would deteriorate almost any receiver, unless you are using a super regenerative. Back-to-back diodes by themselves are a poor enough system. They generate significant intermod with a sum of all signals at .5 volts RMS, which is a sum of signal power (from all signals) of only 7 dBm at 50 ohms or 5.2 dBm into 75 ohms. Back-to-back diodes even deteriorate performance below that threshold with most small fast signal diodes, some fast small signal diodes start to create unwanted mixing products at 0 dBm or less. Back-to-back diodes driven by minicircuits type transformers would be worse yet. I can't use minicircuits transformers on my Beverages here, because of IMD. A properly designed clamp would have no effect up to about 20-23 dBm, where it would clamp hard, and would not include easily-saturated very small core transformers. Be careful with anything that uses back-to-back diodes. 73 Tom ___ Topband reflector - topband@contesting.com
Re: Topband: TX/ RX Antenna Switching
It sounds like the DX and MFJ are out because of Watt limitations (200W?). You are misinterpreting the ratings. The ratings are for power from the transceiver sent out THROUGH the device, not transmitter power to some other system not directly connected to the device. The switches go between the radio and amplifier. This means unless you have a radio with more than 200 watts driving your amplifier, they are fine in the intended application. If you use them as a receiver line limiter or disconnect, and do not intend to transmit through them, the power rating does not apply at all because it is an external system. In that case, the power rating would depend on mutual coupling between transmitting and receiving antennas and impedances of the receiving antenna system. A power rating would be impossible to define because systems vary so much, but it would be many kilowatts even with close antennas. 73 Tom ___ Topband reflector - topband@contesting.com
Re: Topband: TX/ RX Antenna Switching
By the way Buck, there is more to this than some people will tell you. The DXE switch uses a unique RF limiter that kicks in hard at about 23 dBm. Below that level there is no intermod at all!! It will not deteriorate the receiver, like normal cheap back-to-back diode systems. If you need a receiver limiter and do not want to hurt receiver dynamic range on modern receivers, it takes far more circuitry than cheap back-to-back diodes. 73 Tom ___ Topband reflector - topband@contesting.com
Re: Topband: TX/ RX Antenna Switching
Getting away from what we are discussing now (limiters) and back to the original question... it really is just a few bucks for a relay for a rig (without separate T and R jacks) at the 100W level, to add separate T and R based on the amp key line. It's ironic that for most of half a century, the ARRL handbook showed designs for T/R switches, and now those with entry level radios have to build the opposite of the T/R switch to have seperate T/R antennas :-). Tim N3QE From: Topband [topband-boun...@contesting.com] on behalf of Tom W8JI [w...@w8ji.com] Sent: Wednesday, November 14, 2012 4:25 PM To: ZR; Buck wh7dx; topband@contesting.com Subject: Re: Topband: TX/ RX Antenna Switching How do we know what it has with no schematic available? It could be $1-2 worth of parts. I recommend that nobody buy anything from DXE that does not support an at home repair. I certainly agree everyone should give out schematics. Not providing a schematic does not stop anyone from copying something, because anyone can buy one and trace it out. Not providing a schematic only makes things rough for someone trying to repair something, or trouble shoot a system. I see more and more a tendency to not provide schematics, and this is an alarming trend. This goes from my consumer gear (like my home security system) to my Ham gear. Unfortunately, this is very common these days. However, we also should not shoot from the hip and/or present things as fact or present things as something we know when we are just guessing, assuming, or making things up. This goes across the board to all topics. Tom ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: TX/ RX Antenna Switching
On Wed, 2012-11-14 at 23:46 +, Shoppa, Tim wrote: Getting away from what we are discussing now (limiters) and back to the original question... it really is just a few bucks for a relay for a rig (without separate T and R jacks) at the 100W level, to add separate T and R based on the amp key line. It's ironic that for most of half a century, the ARRL handbook showed designs for T/R switches, and now those with entry level radios have to build the opposite of the T/R switch to have seperate T/R antennas :-). Tim N3QE I had assumed, based on discussion, that full break-in QSK must be a requirement per the original post (which I have missed). Apparently it's not. When I switch from transmit to receive I throw ONE switch - not my key or paddles. One. No RF is generated until I do hit the key but only after the switch has been thrown. When I do that I hear several relays click in unison. It's so simple that even *I* can do it. Transmitters, receivers, and transceivers have a terminal on them somewhere to take care of the needed functions within to go from TX mode to RX mode and the other way 'round. Wire your relay(s) to switch the antenna(s) and tickle those T/R terminals. Take advantage. If your rig doesn't have such a terminal (you paid how much for it?) add one. As Tim says, a T/R relay is just too easy. Buy one with 100 NO and 100 NC contacts and have fun (evil grin). Or maybe more relays with fewer contacts. If more clues are needed I can talk more about how mine are wired now and how they have been wired in the past - best done off-list. If it turns out that full break in QSK *is* a requirement..get out the drills, hack saws, chisels, axes, and solder iron and get to work. Or get out the wallet and get a set of radios that will do what you want right out of the box. 73, Bill KU8H ___ Topband reflector - topband@contesting.com
Re: Topband: TX/ RX Antenna Switching
Yes, I didn't get that right and makes sense. Only 50W on my Radio.. 1/2 power into Amp. I'm obviously not electronically edumacated (as they say in Hawaii :-).. just trying to figure out how to reach out without spending an arm/leg or hurting anything :-) I ordered the Array AS-RXFEB to try it out. It's the easiest way to install. I'm going to use the TS-570 for TX and Yaesu 987 for RX. For me, I should be able to tell pretty easily if it works or not I would think? The Beverage itself should be a nice improvement as a directional to NE (Mainland U.S.) What's the RX with and without the product attached to antenna? Can I tell a difference by ear? See an S difference? I would try 5 watts without the filter on and see what it shows? Maxed out? Try 10 watts with and without etc... I looked up the instructions for DX RTR-1 Switch and Diagram 2 is what I'd be using. 811H amp. Beverage, Amp Buffer etc... If I'm not satisfied with Array on 2nd Radio (having to adjust volume might be an annoying issue).. I think the DX is the second choice. http://static.dxengineering.com/global/images/instructions/dxe-rtr-1a-rev1.pdf I'm using a DX Eng. 4 Port Switch for Hex, 40, 80 and 160M dipole. I might go with the Cushcraft MA-160V if not satisfied with Dipole. (limited space and height issues). When everyone was trying to reach PT0S a few days ago.. I was getting clear signals from all over the U.S. East Coast was no problem 5-7 (my noise is usually around S3-4 on low Dipole - with 200ft ocean drop nearby). Not too close to city.. on point. East Coast from me is nearly 5000 miles and it was a pileup. I recorded it on phone to have friend tell me call signs (getting ready to learn CW now). Yesterday.. Noise level was S0-S1. Very quiet. Thank you!! Bryan. [CONFIDENTIALITY AND PRIVACY NOTICE] Information transmitted by this email is proprietary to Mr. Mrs. B and is intended for use only by the individual or entity to which it is addressed, or where ever the hell it ends up, and will almost certainly contain information that will offend a large portion of the population, which isn't our concern. If you are not the intended lucky recipient, or it appears that this mail has been forwarded to you without the proper authority of the Wizard of Email or Al Gore, you are notified that any thought, use, or consumption of this email is entirely your choice. In such case, Bon AppetitNote: A $.02 Internet Tax was charged for receiving this email and all funds were given to some family somewhere in America or the U.N Have a nice day. ___ Topband reflector - topband@contesting.com
Re: Topband: TX/ RX Antenna Switching
How do we know what it has with no schematic available? It could be $1-2 worth of parts. I recommend that nobody buy anything from DXE that does not support an at home repair. Carl KM1H - Original Message - From: Tom W8JI w...@w8ji.com To: Buck wh7dx wh...@hawaii.rr.com; topband@contesting.com Sent: Wednesday, November 14, 2012 8:07 AM Subject: Re: Topband: TX/ RX Antenna Switching By the way Buck, there is more to this than some people will tell you. The DXE switch uses a unique RF limiter that kicks in hard at about 23 dBm. Below that level there is no intermod at all!! It will not deteriorate the receiver, like normal cheap back-to-back diode systems. If you need a receiver limiter and do not want to hurt receiver dynamic range on modern receivers, it takes far more circuitry than cheap back-to-back diodes. 73 Tom ___ Topband reflector - topband@contesting.com - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1427 / Virus Database: 2441/5394 - Release Date: 11/14/12 ___ Topband reflector - topband@contesting.com
Re: Topband: TX/ RX Antenna Switching
Hello Bryan I am very happy with KD9SV products, are very good and easy to use. I have DXPedition II box to select my beverages. FES protection, preamp and you can use it also with radios with no RX capability http://www.radio-ware.com/products/svdxii.htm 73, Jorge CX6VM/CW5W On Mon, 2012-11-12 at 10:37 -1000, Buck wh7dx wrote: I need to figure out what's the best way to connect a beverage antenna for RX and my dipole for TX. I have a TS-570 and I can use the Antenna 1 2 connection - but then I'd need to manually remember to switch when transmitting etc. don't want to damage the beverage. I have a Yaesu 987 that I can use as a dedicated Beverage RX but I'm concerned about overload from TX antenna nearby. I'm using a 811H with about 400-600W showing up on my meter. I use a DX 4 port switch for my 40,80,160 and HEX. So run the Beverage to Antenna 2 or Yaesu? A friend mentioned, that If I'm going to use a foot pedal.. perhaps wiring the PTT? to the Yaesu to switch it into TX with no MIC.. I haven't looked that up yet. Basically, protecting RX by going into TX and no output?? I've seen this MFJ device which sounds like it might work? http://www.mfjenterprises.com/Product.php?productid=MFJ-1708 There is also this DX Engineering device that might work? http://www.dxengineering.com/parts/dxe-rtr-1 It seems to me that most are using a Beverage and TX so it must be very common and simple? Any suggestions? Thank you! Bryan [CONFIDENTIALITY AND PRIVACY NOTICE] Information transmitted by this email is proprietary to Mr. Mrs. B and is intended for use only by the individual or entity to which it is addressed, or where ever the hell it ends up, and will almost certainly contain information that will offend a large portion of the population, which isn't our concern. If you are not the intended lucky recipient, or it appears that this mail has been forwarded to you without the proper authority of the Wizard of Email or Al Gore, you are notified that any thought, use, or consumption of this email is entirely your choice. In such case, Bon AppetitNote: A $.02 Internet Tax was charged for receiving this email and all funds were given to some family somewhere in America or the U.N Have a nice day. ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: TX/ RX Antenna Switching
I use http://www.ok1rr.com/index.php/technical-topics/39-yet-another-front-end-saver From: gali...@comcast.net To: wh...@hawaii.rr.com Date: Tue, 13 Nov 2012 11:24:29 -0500 CC: topband@contesting.com Subject: Re: Topband: TX/ RX Antenna Switching Bryan, I use the DX Engineering RTR-1 Receive Antenna Interface with my old TS-820S and it works great. I use the PTT line to control the RTR-1. It has very fast switching and a very convenient front panel toggle switch to manually switch between RX and TX antennas. It is built like a tank and will handle 200 watts. I highly recommend it. -Joe On Mon, 2012-11-12 at 10:37 -1000, Buck wh7dx wrote: I need to figure out what's the best way to connect a beverage antenna for RX and my dipole for TX. I have a TS-570 and I can use the Antenna 1 2 connection - but then I'd need to manually remember to switch when transmitting etc. don't want to damage the beverage. I have a Yaesu 987 that I can use as a dedicated Beverage RX but I'm concerned about overload from TX antenna nearby. I'm using a 811H with about 400-600W showing up on my meter. I use a DX 4 port switch for my 40,80,160 and HEX. So run the Beverage to Antenna 2 or Yaesu? A friend mentioned, that If I'm going to use a foot pedal.. perhaps wiring the PTT? to the Yaesu to switch it into TX with no MIC.. I haven't looked that up yet. Basically, protecting RX by going into TX and no output?? I've seen this MFJ device which sounds like it might work? http://www.mfjenterprises.com/Product.php?productid=MFJ-1708 There is also this DX Engineering device that might work? http://www.dxengineering.com/parts/dxe-rtr-1 It seems to me that most are using a Beverage and TX so it must be very common and simple? Any suggestions? Thank you! Bryan [CONFIDENTIALITY AND PRIVACY NOTICE] Information transmitted by this email is proprietary to Mr. Mrs. B and is intended for use only by the individual or entity to which it is addressed, or where ever the hell it ends up, and will almost certainly contain information that will offend a large portion of the population, which isn't our concern. If you are not the intended lucky recipient, or it appears that this mail has been forwarded to you without the proper authority of the Wizard of Email or Al Gore, you are notified that any thought, use, or consumption of this email is entirely your choice. In such case, Bon AppetitNote: A $.02 Internet Tax was charged for receiving this email and all funds were given to some family somewhere in America or the U.N Have a nice day. ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: TX/ RX Antenna Switching
Thanks guys. It sounds like the DX and MFJ are out because of Watt limitations (200W?). There are two Front End Savers so far.. KD9SV Front End Saver and OK1RR Saver And there's this.. which sounds simple if I want to use my Yaesu 987 for the Beverage RX only. No changes to main rig config. Just add Box to Yaesu Ant.?? ICE PRODUCT - RF Limit - Signal Protector (just saw this) Limit to S-9 +60DB? With lightning arrestor for $60. Here is a trick unit that is ideal for serious listeners on HF, VHF, and UHF. Receiver protector limits input RF signal threshold at any frequency at 0.3VRMS to protect receiver front end from damage due to nearby transmitted fields. Receiver still acts normally and measured signal strength is not affected. Circuit uses a multi-stage design of transformer saturation coupling and current limiters. Models 196 and 198 are receive RF limiting only, while models 197 and 199 offer the same but with our constant-drain, capacitor-blocked lightning arrestor technology built in to the same unit. For all receivers, especially the new broadband super-sensitive solid state units. Low frequency models are fitted with RCA pin connectors while high frequency units are BNC. N connectors available on request. Chassis measure (HWD) 1 x 2 x 3, weight one pound, packed with 4 page owner's manual / data sheet. [CONFIDENTIALITY AND PRIVACY NOTICE] Information transmitted by this email is proprietary to Mr. Mrs. B and is intended for use only by the individual or entity to which it is addressed, or where ever the hell it ends up, and will almost certainly contain information that will offend a large portion of the population, which isn't our concern. If you are not the intended lucky recipient, or it appears that this mail has been forwarded to you without the proper authority of the Wizard of Email or Al Gore, you are notified that any thought, use, or consumption of this email is entirely your choice. In such case, Bon AppetitNote: A $.02 Internet Tax was charged for receiving this email and all funds were given to some family somewhere in America or the U.N Have a nice day. ___ Topband reflector - topband@contesting.com
Re: Topband: TX/ RX Antenna Switching
Thanks for input. Because I'm using two different radios for TX / RX - This product from Array sounds like a simple fix to RF overload. I think if I was using one radio and needed to switch - I'd go with the other products. I guess I'll see about any volume? issues with that setup?Do my own audio sounds checks??? :-) Turn volume on Beverage RX Yaesu up and down as needed to hear signals not available to TX antenna... ??? I think I should take the advise I was given and move beverage as far away as possible... but probably only 100-150ft is what I have to work with. Bryan WH7DX [CONFIDENTIALITY AND PRIVACY NOTICE] Information transmitted by this email is proprietary to Mr. Mrs. B and is intended for use only by the individual or entity to which it is addressed, or where ever the hell it ends up, and will almost certainly contain information that will offend a large portion of the population, which isn't our concern. If you are not the intended lucky recipient, or it appears that this mail has been forwarded to you without the proper authority of the Wizard of Email or Al Gore, you are notified that any thought, use, or consumption of this email is entirely your choice. In such case, Bon AppetitNote: A $.02 Internet Tax was charged for receiving this email and all funds were given to some family somewhere in America or the U.N Have a nice day. ___ Topband reflector - topband@contesting.com
