2 Meter SSB?

Discussion in 'VHF/UHF - 50Mhz and Beyond' started by N4MTB, Aug 19, 2018.

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  1. KD8TUT

    KD8TUT Platinum Subscriber Platinum Subscriber QRZ Page

    2 meter AM is rare because radios capable of the mode are fairly rare. Even the last gen "All mode" VHF/UHF radios left AM out.

    The new Icom 9700 has AM as I understand it. That might change the activity levels going forward.
     
  2. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    It's certainly good for preventing large stacks of paper from flying away on a windy day.:)
     
  3. KG7ZFC

    KG7ZFC Ham Member QRZ Page

    I've wondered that. Why? Because I like messing with my audio; I'm one of those setting up audio equipment in a rack and feeding it with a semi-pro mic and tweaking things. I might even do HF ESSB. :p 2M AM would be awesome, especially if we could widen the signal a bit to get some wonderful audio.

    Easiest way? Good HF rig with AM and one of the Ukrainian transverters off of eBay for 2m for $80 plus $15 shipping. Fire up 10m on the HF rig, lower power, feed into transverter, and out would come a couple of watts of 2m AM. Of course, this could be used for any mode, like SSB, too.

    On another note, there's a 6m AM net 2 or 3 times a week here in the Seattle area on 50.4 MHz. I think it's Sunday/Wed/Fri at 9:00PM (Sunday I'm sure of, but I think the other days happen, too).
     
  4. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    AM faded away on VHF-UHF mostly because the serious ops are "weak signal" ops and SSB/CW/digital is way better for weak signals than AM is.

    For "fidelity," AM is still better! But it won't support the typical 400-mile SSB QSOs we have on SSB unless you have one hell of a station.

    I ran 1kW on 2m and 6m AM back in the sixties. Big antennas, sensitive receivers. But for "DXing" still always had to resort to CW to stretch it that last couple hundred miles, and that's where most of the contacts were.
     
  5. WA7KKP

    WA7KKP Ham Member QRZ Page

    2M SSB is still used mainly for satellite comms, but I do know that a sizeable group of hams in KS and MO discovered that SSB mobile was out-performing FM and existing repeaters.

    I got a Kenwood TR-9130 all mode xcvr for nothing, and I'm going to find out for myself.

    Gary WA7KKP
     
  6. KI7AAR

    KI7AAR Premium Subscriber QRZ Page

    I’m anxious to try 2m ssb. Will start will a M2 5WL yagi at 70’, a Lunar 300W amp and my Flex-5000VU. There are hills and trees so it may work and may not. Another 20’ of elevation to get out to the west would be better but, it was outside of my budget to add a 6N62 section to the Rohn SSV HD. The coax run from the rig to the antenna is about 150’. A Heliax run or mounting the amp on the tower may be necessary. I’m pouring the tower foundation this Friday so it’s still a ways out.
     
  7. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    I wouldn't mount the amp outside.

    1/2" hardline at 150' only has about 1.35 dB loss and is pretty available. Of course "topside" you'll need flex line around the rotator, so maybe another 0.3 - 0.4 dB for that (LMR400UF or whatever) but still likel <2 dB overall, which isn't bad at all.

    "If you can" and don't already own the 2M5WL, I'd recommend stacked shorter boom antennas instead (if possible). Reason: 2M5WL is razor-sharp in azimuth and I've used them many times -- great antenna, but quite literally the 2-3 degrees of rocking a long beam can exhibit on windy days can actually cause QSB you can see and hear because it's just so sharp. A pair of stacked (one above another) yagis of half the boom length will have the same gain without that problem, makes it easier on the rotator and everything else.
     
    WD4IGX likes this.
  8. KI7AAR

    KI7AAR Premium Subscriber QRZ Page

    Understood on the feedline losses. I was thinking 7/8”or larger hard line because I wouldn’t mind placing a 432 yagi on the same tower if the 2m works out. Placing the amp on the tower in a ventilated weatherproof cabinet would allow me to see if 2m is going to work out before investing in an expensive feed line. I could always use the cabinet later for a remote station that is a few projects out.

    What is the disadvantage of permanently mounting the amp on or near the tower if a ventilated weatherproof cabinet is utilized? There will be an RX preamp on the tower anyway and that extra 1 dB or so on TX might come in handy someday.
     
  9. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    You'd also need to mount a high current 14Vdc power supply in the same cabinet to power the amp, so besides coax and a PTT control line, you'd need 120Vac run to the same cabinet. Probably not a big deal, but another consideration. And that amp requires quite a lot of "ventilation," so I'd add a fan or fans to the vents and force a lot of air through it. Outside, that usually means a lot of insects, so screens over the vents -- which will get clogged with bugs over time, so just another thing to "maintain."

    If you're in a location where the temperature can drop below freezing, the amplifier gain will suffer and sometimes relays stop working well if they get too cold. "Automotive" components often work quite well down to below 0F, but "amateur radio" components quite often don't -- they weren't selected for that.

    Just stuff to think about, since I've done the "remote solid state amp" stuff before and below about 1296 MHz, found it just isn't worth it. At 5.7 or 10.3 GHz, everybody does it and there isn't much other choice.:p
     
  10. KI7AAR

    KI7AAR Premium Subscriber QRZ Page

    Good points, Steven. I was thinking of using a surplus cabinet that was intended for this type of thing and I’m not that concerned about running power to the tower. Other than the lightning risk...

    Anyway, your probably right. Take the hit on line loss and save the extra effort. If it actually gets out from my location then a legal limit 2m legal limit amp build might be fun at some point.
     

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