Questions from an absolute VHF lowband propagation lowband newbie

[KB2GOM]

Been hanging out on RR for while, but I just noticed the skip/tropospheric ducting forum today, and I found the long-range VHF/lowband logs fascinating.

So I've reached out to a couple of you by PM to find out how you do it, but on further thought, it seemed a good idea to post my questions publicly.

1. What is your basic strategy to find this long-range propagation?
2. Do you do a search across a range of frequencies?
3. or do you load up a group of specific frequencies and search those?
or is it something else?

My "best" antenna is the off-center fed dipole mentioned frequently on these forums. I hooked it up to my Uniden 125 and searched from 29 MHz to 49 MHz. I'm based just outside Troy, NY. Several times, I got hits on 46.360. Seemed to be EMS calls. Streets were mentioned but no towns, so I don't know the origin of the signals.

Any advice or counsel you can offer (or point me in the right direction) would be greatly appreciated.

 

[popnokick]

Jock - A couple things come to mind: 1) Since you are using the RR Wiki Off-Center Fed Dipole you need to know that in the low band freqs (30-50 mHz and some below) the feed line becomes part of the antenna. In my case that's a GOOD thing because I have a very long (60-70 feet) of RG6 feeding my OCFD. I'm fairly certain this helps my VHF low band reception. I regularly get low band transmissions from assorted fire departments within a 50 mile radius even without a "band opening". 2) To ensure I"m alerted to band openings (both VHF Lowband and 10 Meters) I have programmed all of the CB channels into my scanner. When I start hearing, "How boutcha, how bouthcha out there in skip land... come on back..." on any CB channel I know that VHF Lo and 10 Meters will be running open. I then disable the Favorites list containing CB and leave the rest of VHF Low enabled.

 

[KB2GOM]

Jock - A couple things come to mind: 1) Since you are using the RR Wiki Off-Center Fed Dipole you need to know that in the low band freqs (30-50 mHz and some below) the feed line becomes part of the antenna. In my case that's a GOOD thing because I have a very long (60-70 feet) of RG6 feeding my OCFD. I'm fairly certain this helps my VHF low band reception. I regularly get low band transmissions from assorted fire departments within a 50 mile radius even without a "band opening". 2) To ensure I"m alerted to band openings (both VHF Lowband and 10 Meters) I have programmed all of the CB channels into my scanner. When I start hearing, "How boutcha, how bouthcha out there in skip land... come on back..." on any CB channel I know that VHF Lo and 10 Meters will be running open. I then disable the Favorites list containing CB and leave the rest of VHF Low enabled.

Pop, makes perfect sense . . . use CB as your "canary in the coal mine" to detect when the "skip" is running. Unfortunately, since my off-center fed dipole hangs indoors in a corner of my shack, my feedline is about 6 feet long. However, I can considering upgrading my outdoor 2-meter antenna, and if I went with the Comet GP-15, that would give me 6 meters . . . which is close enough.

Good to hear from you.

Cheers, Jock

 

[west-pac]

Pop, makes perfect sense . . . use CB as your "canary in the coal mine" to detect when the "skip" is running. Unfortunately, since my off-center fed dipole hangs indoors in a corner of my shack, my feedline is about 6 feet long. However, I can considering upgrading my outdoor 2-meter antenna, and if I went with the Comet GP-15, that would give me 6 meters . . . which is close enough.

Good to hear from you.

Cheers, Jock

FWIW, the GP15 is a GREAT antenna. I worked many states on 50Mhz with one, even though they're designed for 52Mhz.

 

[KB2GOM]

FWIW, the GP15 is a GREAT antenna. I worked many states on 50Mhz with one, even though they're designed for 52Mhz.

Working on FM or SSB or CW?

 

[west-pac]

Working on FM or SSB or CW?

50Mhz is SSB, 52Mhz is FM.

 

[KB2GOM]

50Mhz is SSB, 52Mhz is FM.

Okay . . . shows my lack of knowledge.

So you are working 6m SSB DX with a vertically polarized antenna . . . do I have that right?

 

[west-pac]

Okay . . . shows my lack of knowledge.

So you are working 6m SSB DX with a vertically polarized antenna . . . do I have that right?

Correct. I did for a few years before I went to a 6M halo.

 

[KB2GOM]

Correct. I did for a few years before I went to a 6M halo.

Wow. That's good to know. I was told that horizontal polarization was basically a necessity to have any success at all. I'm thinking the GP-15 for now and think about a halo or omniangle on the same pole a bit later.

Basically, all I do on the transmitting end of things is this -- Commuter Assistance Net . If you are wildly curious about the net, I did an interview with the Scanner Guys about it:

30 years ago, I worked the world on 10 meters with a small beam hooked to my chimney. Now I want to keep things simple if I can.

Thanks for the info!

 

[Ishmole]

Aren't most 6 meter SSB comms horizontally polarized, and the FM transmissions vertically polarized?

 

[nd5y]

Aren't most 6 meter SSB comms horizontally polarized, and the FM transmissions vertically polarized?

Yes, but that's only important for local communications. Ionospheric propagation causes polarization to change randomly so antenna polarization usually doesn't make much difference.

 

[Ishmole]

Yes, but that's only important for local communications. Ionospheric propagation causes polarization to change randomly so antenna polarization usually doesn't make much difference.

You are right. I forgot that! Thanks!