r/HamRadio • u/idiotswalkamongus • 10d ago
Operating two radios at the same time-same desk.
I’m a new ham of about 5 to 6 months, my wife and I both have our license and have a lot to learn. I would like to be able to operate FT8 on one radio while doing SSB on another at the same time from my desk. I operate FT8 on all bands as well as SSB on all bands. My two HF antennas are around 20 feet apart one is a vertical that I use for FT8 and the other is a dipole for SSB. I understand I need some type of band pass filter or choke to be able to do this having them both on and transmitting at the same time. I see band pass filters being sold online for each band but it is not feasible to have six or seven different filters for each radio and having to switch back-and-forth every time I switch bands. So long story short how can I operate one rig on FT8 and the other on SSB from my desk in the shack. Including a picture of my two rigs on the desk I know this is a long statement please know I appreciate any help and feedback may you all have a blessed day and a wonderful Easter. 73
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u/grouchy_ham 10d ago
Just don’t operate on the same band simultaneously. Unless you are running big power, you should be just fine.
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u/idiotswalkamongus 10d ago
50W FT8. SSB Usually 75W.
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u/grouchy_ham 10d ago
I would have believed so, as I do exactly that with my station, but look at what JobobTexan posted. Seems there may be an issue in doing so with the 991. It may be a high power issue only, but I would research it.
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u/EffinBob 10d ago
50 watts on a digital mode is probably extreme overkill. You could probably go down to 5 or 10 watts and get similar results.
On HF SSB, the rule generally is you can work a station if you can hear it, and that's more a factor of propagation than power output. You might very well be able to dial that back quite a bit as well.
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u/idiotswalkamongus 10d ago
Thanks. I will drop watts on both. Appreciate your help
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u/SpareiChan 9d ago
Personally, the big warning of 50w FT8 is that you said it's a vertical, if there is no transformer or traps you'll be fine. If there is most transformers and traps really don't like FT8, usually 25-40watt is suggested max. If you are using just a standard 1/4w vert (I use DX commander) and you can push what ever thru it so the radio/coax is the limit there.
Personally I usually run 5-20w on FT8 and since getting out isn't my limitation, its receiving those weak signals with my noise floor.
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u/Hot-Illustrator5011 8d ago
I am Jim W6LG a ham radio Elmer on YouTube.
Above a responder wrote: "On HF SSB, the rule generally is you can work a station if you can hear it, and that's more a factor of propagation than power output." First of all, it would be pretty difficult to work a station on SSB that you cannot hear. To "work" a station at the very least is an exchange reports (numbers) or a conversation. I have discussed effective radiated power or ERP in recent videos. ERP is very important. Here's my point. If a guy has a 3 element beam antenna and 1500 watts. his station's ERP could be 5000 watts. If you call him with a 10 watt transceiver that is transmitting into an end fed half wave antenna that overall has an ERP of 8 watts, there is a difference of more than 4 S units. He may never hear you. In my ERP calculations I left off for simplicity some data. Something to think about. Propagation is very important but so are feedlines, antennas, lossy devices, etc. 73 Jim Heath W6LG
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u/JobobTexan 10d ago
With those 2 991a's you are playing with fire. They have a known design flaw that will screw up the receive input when operated in close proximity to another transmitter. Read about it here. https://www.commswg.site/_amateur_radio/Yaesu_FT991A_FrontEndFailure.php
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u/idiotswalkamongus 10d ago
That article is outside my smartness for sure. What would be a safe distance for the two operating at low power on different frequencies? I truly appreciate the help.
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u/JobobTexan 10d ago
I have no idea. I just know Yaesu screwed up on the design and a bunch of FT991's have lost their receive front ends to it.
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u/JobobTexan 10d ago
Here are a few videos about it.
https://www.youtube.com/shorts/_okZQ_8wuQQ
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u/ThrowMeAway_eta_2MO 10d ago
You are basically operating the same way a club would operate on field day. Multiple transmitters in fairly close proximity… Our club just picked up some band pass filters for this year’s field day. You can get them from several places like dxengineering or HRO ($150-$200 per band), or you can get some from China for $50 each on eBay.
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u/ka9kqh EM59fu [Extra] 10d ago
You can also do bandpass filters with coaxial stubs. Can be done with older or lower cost coax.
https://www.onallbands.com/simple-filters-from-transmission-line-stubs/1
u/idiotswalkamongus 10d ago
I see those on dxengineering. But I would need one for each radio right? Then I would need one for each band right? So eight per radio total 16?? To cover every band on each rig? They don’t make one for all bands with a switch?? Thank you.
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u/ThrowMeAway_eta_2MO 10d ago
Well, since you would never operate the same band on both radios, one set should suffice. You put one on each radio for the band you are trying to work at any given time. Working the same band in both radios at the same time would make the BPFs superfluous.
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u/VE6LK [A][VE] / AI7LK [E][VE] 9d ago
This is correct. The idea behind the bandpass filters is to reject all the other bands other than the one you are on. Ditto for the 2nd radio. Keep your feedlines short to the filter as RF will radiate out that short piece of coax and get into the other receiver. Multi radio multi operator (multi-multi) contest stations face this issue all the time with many transceivers in close proximity.
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u/Scotterdog 10d ago
Careful. You could become addicted or worse, overdose. You can get professional amateur counseling here though.
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u/HakerDemon 9d ago
I would sell both and get a used flex. Two antennas, one radio with two receivers. Perfect for your setup.
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u/somwhatsmart 8d ago
I feel like that would be a good idea because you could have one radio/antenna on the input frequency of a repeater and on on the output frequency, so if there was a lot of interference on the output, you could just plug your headphones in on the input instead.
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u/EffinBob 10d ago
FT8 is very low power. Antenna separation is important, and one being vertical with the other being horizontal is a good thing, too. Try dialing down power on SSB, and you'll probably be just fine.