jury rigged vhf receiver
I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF
radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Jimmie |
jury rigged vhf receiver
JIMMIE wrote:
I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Jimmie For best performance these mixers require a constant impedance at all three ports (usually 50 ohms). The preamp will provide this for the RF input and the output of your HP signal generator should have a 50 ohm selectable output. You may need to add an attenuator between the generator and the mixer if the HP does not provide a 50 ohm termination using a variable output. You will need to set the oscillator injection level to the mixers required 7dbm drive level for best conversion "gain". The output should go through a bandpass filter covering the IF frequency you are down converting to and provide a 50 ohm impedance. A duplexer network here is a good idea (provides a 50 ohm termination at the IF frequency and a low impedance (short) to ground to out of IF signals). |
jury rigged vhf receiver
On Jan 23, 6:43*pm, Kenneth Scharf wrote:
JIMMIE wrote: I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Jimmie For best performance these mixers require a constant impedance at all three ports (usually 50 ohms). *The preamp will provide this for the RF input and the output of your HP signal generator should have a 50 ohm selectable output. *You may need to add an attenuator between the generator and the mixer if the HP does not provide a 50 ohm termination using a variable output. *You will need to set the oscillator injection level to the mixers required 7dbm drive level for best conversion "gain". *The output should go through a bandpass filter covering the IF * frequency you are down converting to and provide a 50 ohm impedance. A duplexer network here is a good idea (provides a 50 ohm termination at the IF frequency and a low impedance (short) to ground to out of IF signals). Any reccomendation on the best mixer to use? Jimmie |
jury rigged vhf receiver
JIMMIE wrote:
On Jan 23, 6:43 pm, Kenneth Scharf wrote: JIMMIE wrote: I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Jimmie For best performance these mixers require a constant impedance at all three ports (usually 50 ohms). The preamp will provide this for the RF input and the output of your HP signal generator should have a 50 ohm selectable output. You may need to add an attenuator between the generator and the mixer if the HP does not provide a 50 ohm termination using a variable output. You will need to set the oscillator injection level to the mixers required 7dbm drive level for best conversion "gain". The output should go through a bandpass filter covering the IF frequency you are down converting to and provide a 50 ohm impedance. A duplexer network here is a good idea (provides a 50 ohm termination at the IF frequency and a low impedance (short) to ground to out of IF signals). Any reccomendation on the best mixer to use? Jimmie Here's one good to about 600 MHz. Been used a gazillion times in just about all VHF/UHF transverters at one time or another. If casual listening is all you need, hook it up just like you said...VHF/UHF antenna to the RF port, HP signal generator to LO port (set to +7 dBm output for this mixer and frequency appropriate for your IF frequency such as 116 MHz for 144 MHz to be 28 MHz out of the mixer) and connect the mixer IF pin to your HF radio antenna port. Probably a good idea to use capacitor coupling at each mixer port, something like 1000pF should work. http://www.minicircuits.com/pdfs/TUF-1+.pdf Scott N0EDV |
jury rigged vhf receiver
JIMMIE wrote:
I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Just as an experiment, I once used the mixer & LO in one of my FM rigs. Just tapped the output of the mixer just before the IF filter, ran it through a DC-blocking capacitor out to the antenna input of a general-coverage HF receiver. Tuned the HF rig to 10.7MHz - sure enough, there were the 2m SSB (and CW) signals. Worked pretty well. It was pretty cumbersome to tune though. Luckily, almost everyone around here is within 5KHz of 144.200... Didn't take long to get the urge to transmit, at which point I wimped out & bought a multimode rig... -- Doug Smith W9WI Pleasant View, TN EM66 |
jury rigged vhf receiver
sorry-spammers wrote:
Luckily, almost everyone around here is within 5KHz of 144.200... "Lucky" depends on how many locals there are ;) If you have 10 or 20 local weak signal VHFers, it could get a bit messy ;) Scott, N0EDV EN45fa |
jury rigged vhf receiver
Scott wrote:
JIMMIE wrote: On Jan 23, 6:43 pm, Kenneth Scharf wrote: JIMMIE wrote: I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Jimmie For best performance these mixers require a constant impedance at all three ports (usually 50 ohms). The preamp will provide this for the RF input and the output of your HP signal generator should have a 50 ohm selectable output. You may need to add an attenuator between the generator and the mixer if the HP does not provide a 50 ohm termination using a variable output. You will need to set the oscillator injection level to the mixers required 7dbm drive level for best conversion "gain". The output should go through a bandpass filter covering the IF frequency you are down converting to and provide a 50 ohm impedance. A duplexer network here is a good idea (provides a 50 ohm termination at the IF frequency and a low impedance (short) to ground to out of IF signals). Any reccomendation on the best mixer to use? Jimmie Here's one good to about 600 MHz. Been used a gazillion times in just about all VHF/UHF transverters at one time or another. If casual listening is all you need, hook it up just like you said...VHF/UHF antenna to the RF port, HP signal generator to LO port (set to +7 dBm output for this mixer and frequency appropriate for your IF frequency such as 116 MHz for 144 MHz to be 28 MHz out of the mixer) and connect the mixer IF pin to your HF radio antenna port. Probably a good idea to use capacitor coupling at each mixer port, something like 1000pF should work. http://www.minicircuits.com/pdfs/TUF-1+.pdf Scott N0EDV For what it's worth, that's the same mixer used in the Elecraft K2 receiver section. |
jury rigged vhf receiver
On Jan 24, 10:51*am, Kenneth Scharf wrote:
Scott wrote: JIMMIE wrote: On Jan 23, 6:43 pm, Kenneth Scharf wrote: JIMMIE wrote: I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Jimmie For best performance these mixers require a constant impedance at all three ports (usually 50 ohms). *The preamp will provide this for the RF input and the output of your HP signal generator should have a 50 ohm selectable output. *You may need to add an attenuator between the generator and the mixer if the HP does not provide a 50 ohm termination using a variable output. *You will need to set the oscillator injection level to the mixers required 7dbm drive level for best conversion "gain". *The output should go through a bandpass filter covering the IF * frequency you are down converting to and provide a 50 ohm impedance. A duplexer network here is a good idea (provides a 50 ohm termination at the IF frequency and a low impedance (short) to ground to out of IF signals). Any reccomendation on the best mixer to use? Jimmie Here's one good to about 600 MHz. *Been used a gazillion times in just about all VHF/UHF transverters at one time or another. *If casual listening is all you need, hook it up just like you said...VHF/UHF antenna to the RF port, HP signal generator to LO port (set to +7 dBm output for this mixer and frequency appropriate for your IF frequency such as 116 MHz for 144 MHz to be 28 MHz out of the mixer) and connect the mixer IF pin to your HF radio antenna port. *Probably a good idea to use capacitor coupling at each mixer port, something like 1000pF should work. http://www.minicircuits.com/pdfs/TUF-1+.pdf Scott N0EDV For what it's worth, that's the same mixer used in the Elecraft K2 receiver section.- Hide quoted text - - Show quoted text - Thanks all , I found some little boxes in my scrap pile withe 3 SMA connectors on each one. Plan is to get a couple or 3 of the mixers and mount them in the boxes. Having a mixer in a box may be fun to play with. Jimmie |
jury rigged vhf receiver
On Jan 24, 10:03*am, sorry-spammers ""w9wi\"@(sorry-spammers)"
wrote: JIMMIE wrote: I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Just as an experiment, I once used the mixer & LO in one of my FM rigs. *Just tapped the output of the mixer just before the IF filter, ran it through a DC-blocking capacitor out to the antenna input of a general-coverage HF receiver. *Tuned the HF rig to 10.7MHz - sure enough, there were the 2m SSB (and CW) signals. *Worked pretty well. It was pretty cumbersome to tune though. *Luckily, almost everyone around here is within 5KHz of 144.200... Didn't take long to get the urge to transmit, at which point I wimped out & bought a multimode rig... -- Doug Smith W9WI Pleasant View, TN *EM66 Thats a thought, I might do that with an old mobile unit I have in the junk box. I think it will rx but the tx is dead. See if I can pick the signal off right after the first mixer. Jimmiej |
jury rigged vhf receiver
On Sat, 23 Jan 2010 14:52:14 -0800, JIMMIE wrote:
I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Jimmie Performance won't be optimal, and you'll get some LO leakage. You may want to consider trapping the LO back toward the antenna, or using a preamp just to block the radiation. Or just lash the dang thing together and see how it works. -- www.wescottdesign.com |
jury rigged vhf receiver
On Sat, 23 Jan 2010 14:52:14 -0800, JIMMIE wrote:
I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Jimmie Do let us know what you tried, and how it worked. -- www.wescottdesign.com |
jury rigged vhf receiver
On Jan 24, 6:21*pm, Tim Wescott wrote:
On Sat, 23 Jan 2010 14:52:14 -0800, JIMMIE wrote: I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Jimmie Do let us know what you tried, and how it worked. --www.wescottdesign.com OK where can you get a TUF-1 Jimmie |
jury rigged vhf receiver
JIMMIE wrote:
On Jan 24, 6:21 pm, Tim Wescott wrote: On Sat, 23 Jan 2010 14:52:14 -0800, JIMMIE wrote: I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Jimmie Do let us know what you tried, and how it worked. --www.wescottdesign.com OK where can you get a TUF-1 Jimmie Direct from Mini Circuits http://www.minicircuits.com/cgi-bin/...rch_type=model or Downeast Microwave in the "components" section http://www.downeastmicrowave.com/cat-frame.htm Minicircuits is $7.50 each, Downeast is $18 each. I assume both will have a shipping charge. Scott N0EDV |
jury rigged vhf receiver
On Jan 24, 8:47*pm, Scott wrote:
JIMMIE wrote: On Jan 24, 6:21 pm, Tim Wescott wrote: On Sat, 23 Jan 2010 14:52:14 -0800, JIMMIE wrote: I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Jimmie Do let us know what you tried, and how it worked. --www.wescottdesign.com OK where can you get a TUF-1 Jimmie Direct from Mini Circuitshttp://www.minicircuits.com/cgi-bin/modelsearch?model=TUF-1%2B&search... or Downeast Microwave in the "components" sectionhttp://www.downeastmicrowave.com/cat-frame.htm Minicircuits is $7.50 each, Downeast is $18 each. *I assume both will have a shipping charge. Scott N0EDV- Hide quoted text - - Show quoted text - Thanks I was under the impression the minicircuits has a minimum order. Jimmie |
jury rigged vhf receiver
JIMMIE wrote:
Thanks I was under the impression the minicircuits has a minimum order. Jimmie Not that I'm aware of :) I've ordered small quantities from them in the past.... |
jury rigged vhf receiver
Scott wrote:
sorry-spammers wrote: Luckily, almost everyone around here is within 5KHz of 144.200... "Lucky" depends on how many locals there are ;) If you have 10 or 20 local weak signal VHFers, it could get a bit messy ;) Around here, it was in fact lucky..... (managed an entire 15 QSOs in this weekend's contest, as a rover operation. (admittedly only two grids...)) -- Doug Smith W9WI Pleasant View, TN EM66 |
jury rigged vhf receiver
sorry-spammers wrote:
(managed an entire 15 QSOs in this weekend's contest, as a rover operation. (admittedly only two grids...)) Yes, the bands were kinda flat. Plus, we had RAIN on Saturday and wet snow on Sunday here in WI (which REALLY sucks)...Sunday brought high SWR on the 6M antenna so I couldn't use it and didn't hear a peep on 2M. And with the crummy precip, I had no desire to rove or set up the portable antennas on 222, 432, 902 or 10 GHz.... |
jury rigged vhf receiver
On Jan 24, 6:21*pm, Tim Wescott wrote:
On Sat, 23 Jan 2010 14:52:14 -0800, JIMMIE wrote: I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Jimmie Do let us know what you tried, and how it worked. --www.wescottdesign.com UPS delivered the mixer yesterday evening but I didnt get to play with it until this AM.Im working evenings. I spent about an hour getting it connected up. There may not have been any SSB activity but I was able to hear all the usual local 2m repeaters using my HF rig set up for 10M FM. Setup was as about as simple as it gets. With pre- amp at the antenna, antenna , receiver and osc was just connected directly to the mixer with some small coax alledged to be 50 ohms. At this thime I really cant evaluate it more than that. Jimmie |
jury rigged vhf receiver
On Fri, 29 Jan 2010 13:07:30 -0800, JIMMIE wrote:
On Jan 24, 6:21Â*pm, Tim Wescott wrote: On Sat, 23 Jan 2010 14:52:14 -0800, JIMMIE wrote: I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Jimmie Do let us know what you tried, and how it worked. --www.wescottdesign.com UPS delivered the mixer yesterday evening but I didnt get to play with it until this AM.Im working evenings. I spent about an hour getting it connected up. There may not have been any SSB activity but I was able to hear all the usual local 2m repeaters using my HF rig set up for 10M FM. Setup was as about as simple as it gets. With pre- amp at the antenna, antenna , receiver and osc was just connected directly to the mixer with some small coax alledged to be 50 ohms. At this thime I really cant evaluate it more than that. The bands always go dead right when you finish a radio. Keep us posted. -- www.wescottdesign.com |
jury rigged vhf receiver
On Jan 29, 9:24*pm, Tim Wescott wrote:
On Fri, 29 Jan 2010 13:07:30 -0800, JIMMIE wrote: On Jan 24, 6:21*pm, Tim Wescott wrote: On Sat, 23 Jan 2010 14:52:14 -0800, JIMMIE wrote: I was wanting to listen to VHF/UHF SSB. All of my present UHF/VHF radios are FM. I was thinking of rigging up a simple downconverter using a mini circuit mixer and my HP signal generator as the local oscilator that I can connect in front of my HF rig. I have an antenna mounted pre- amp that I think should suffice for my front end. Any foreseeable problems short of keying my transmitter while it is connected. Jimmie Do let us know what you tried, and how it worked. --www.wescottdesign.com UPS delivered the mixer yesterday evening but I didnt get to play with it until this AM.Im working evenings. I spent about an hour getting it connected up. There may not have been any SSB activity but I was able to hear all the usual local 2m repeaters using my HF rig set up for 10M FM.. Setup was as about as simple as it gets. With pre- amp at the antenna, antenna , receiver and osc was just connected directly to the mixer with some small coax alleged to be 50 ohms. At this thime I really cant evaluate it more than that. The bands always go dead right when you finish a radio. Keep us posted. --www.wescottdesign.com Seems to be overloading a little on strong signals. This is probably the reason rreal receivers arent quite so simple. Jimmie |
jury rigged vhf receiver
JIMMIE wrote:
UPS delivered the mixer yesterday evening but I didnt get to play with it until this AM.Im working evenings. I spent about an hour getting it connected up. There may not have been any SSB activity but I was able to hear all the usual local 2m repeaters using my HF rig set up for 10M FM. How is SSB activity in your area these days? Over here (Netherlands) it never was as big as FM and one would not expect to hear much in the morning hours, when many hams are at work. But these days, even during evening hours there is not much SSB to be heard anymore. There seems to be activity only during band openings and contests. |
jury rigged vhf receiver
On Feb 1, 2:10*pm, Rob wrote:
JIMMIE wrote: UPS delivered the mixer yesterday evening but I didnt get to play with it until this AM.Im working evenings. I spent about an hour getting it connected up. There may not have been any SSB activity but I was able to hear all the usual local 2m repeaters using my HF rig set up for 10M FM. How is SSB activity in your area these days? Over here (Netherlands) it never was as big as FM and one would not expect to hear much in the morning hours, when many hams are at work. But these days, even during evening hours there is not much SSB to be heard anymore. *There seems to be activity only during band openings and contests. Same here, I had to call someone to get him to give me some test counts on SSB to test my lash up. Jimmie |
All times are GMT +1. The time now is 12:34 PM. |
Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
RadioBanter.com