Radio Preppers

General Category => VHF and Above => Topic started by: gil on June 21, 2017, 08:11:21 AM

Title: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: gil on June 21, 2017, 08:11:21 AM
Hello,

Guess what I'm getting next week in the mail?

(http://radiopreppers.com/images/IC-251E_s.jpg)

Yep, an Icom IC-251E 2m all-modes transceiver.

I want to explore the usefulness of VHF SSB for prepping, as opposed to FM or NVIS on lower bands. I don't think 2m USB will be that much better than FM using a high-gain Yag-Uda directional antenna, but it should still have an edge. I still think NVIS on 80m will beat anything for regional comms, but has any of you guys tried 2m SSB? What is your opinion?

I am building this antenna right now: https://m0ukd.com/homebrew/antennas/144mhz-2m-portable-yagi-vhf-beam-antenna/ (https://m0ukd.com/homebrew/antennas/144mhz-2m-portable-yagi-vhf-beam-antenna/)

Gil.
Title: Re: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: KK0G on June 21, 2017, 08:50:38 AM
I dabbled in VHF weak signal a little quite a few years ago but I'm far from highly experienced, here's what I learned; antenna gain is everything, but let me explain. By antenna gain I mean total gain as in antenna height, gain of the antenna itself, minimal signal attenuation in feedline, antenna polarization, etc. They don't call it weak signal for no reason and a lot of he quick and dirty set ups commonly used on VHF FM don't work well on extremely weak signals.
Title: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: Jon_Garfio on June 21, 2017, 10:22:12 AM
If you want a little and portable prepper yagui antenna watch this:

http://www.qsl.net/xe3rlr/antvhf2.htm




Enviado desde mi iPhone utilizando Tapatalk Pro
Title: Re: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: cockpitbob on June 21, 2017, 04:22:25 PM
I wish I could find that article where Boy Scouts were camping and doing 2M work.  They made a 3 element Yagi with a tree branch and some barbed wire and talked off a mountain top repeater many miles away.  The rusty barbed wire on the crooked stick looked awesome.
Title: Re: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: gil on June 22, 2017, 03:04:30 AM
Thanks Guys. :)

I got the IC-251E from a German seller on Ebay, too cheap to pass...

I wonder is a preamp might be useful... I need to test the rig without one first of course, and the goal is to be heard as well. I ordered a CTCSS tone board to be able to use it on the local FM repeater as well. 10W isn't a lot for weak signal VHF, but I have seen plenty of people do it on Youtube. There are tons of old 2m SSB rigs on Ebay, often for less than $100. I paid $200, but this one is in excellent shape and the model I wanted. I used to have an IC-271A which I never used for SSB, what a shame, but a great radio too. I almost got the MFJ-9402 but it was going to cost me double with import taxes.

The 6-el Yagi-Uda is half-way done, video in the works...

BTW, anyone knows what type of connector is used for DC, a 4-pin in-line type? I can't seem to be able to find a new one...

Gil.
Title: Re: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: KK0G on June 22, 2017, 08:36:22 AM
Quote from: gil on June 22, 2017, 03:04:30 AM

BTW, anyone knows what type of connector is used for DC, a 4-pin in-line type? I can't seem to be able to find a new one...

Gil.


I did a Google image search and that looks like a standard Molex four pin connector to me.
Title: Re: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: gil on June 22, 2017, 09:18:26 AM
Looks like it, yes. Thanks!
Gil

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Title: Re: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: Bigguy49 on June 22, 2017, 10:04:05 PM
Use to work into Colgate Ok and central Texas (Waco, Ft Hood ) from East Dallas with no more than a 7 element beam horizontal and I think 12 watts out on my old Icom all mode mobile rig

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Title: Re: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: gil on June 23, 2017, 06:26:25 AM
QuoteUse to work into Colgate Ok and central Texas (Waco, Ft Hood ) from East Dallas

How far is it?

Gil.
Title: Re: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: caulktel on June 24, 2017, 12:58:15 PM
Hi Gil,

A Ham friend of mine gave me the US version because it didn't work. I was able to restore it back to working order. It is a great radio.

Joel
N6ALT
Title: Re: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: gil on June 25, 2017, 04:46:45 AM
Nice looking one too Joel! I need to find an original microphone.. The one I ordered is a no-brand replacement. No contact yet but I am trying using CW since I don't have the mic yet. I did hear some SSB activity around here though. My homebuilt portable 6-el Yagi-Uda seems to work well, SWR 1.3:1, up to 2:1 at 144.7MHz.

Gil.
Title: Re: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: caulktel on June 25, 2017, 05:20:55 PM
Thanks Gil, I'm rather proud of my IC-251A. I'm using it with a halo antenna right now and it seems to work very good with low SWR. I also have a small 40 watt 2 meter amp, but have not had to use it yet. I'm mostly working local SSB right now. Where did you find a CTCSS board? I would have though those would be hard to find by now. I had to completely rebuild the mic, but it sounds good now and has the DTMF pad in it. Great old radio.

Joel
N6ALT
Title: Re: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: Bigguy49 on June 25, 2017, 11:54:24 PM
Quote from: gil on June 23, 2017, 06:26:25 AM
QuoteUse to work into Colgate Ok and central Texas (Waco, Ft Hood ) from East Dallas

How far is it?

Gil.
From Mesquite Tx  to Colgate Ok is roughly 140 miles ,and to Ft Hood, Killeen is about the same.

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Title: Re: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: gil on June 26, 2017, 01:54:35 AM
FB Bigguy!

Joel, I found a board on EBay, from a South African seller. There are plenty from China. Now I need to find out where to inject the tone.. Presumably it is printed on the PCB but I haven't found it..

Gil

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Title: Re: VHF SSB for Local/Regional Comms? And IC-251E...
Post by: gil on June 27, 2017, 05:42:37 AM
First contact with the IC-251E in USB! Only 20km, but hey, it works! We both were using Yagi-Uda antennas, horizontally polarized. No surprise, S9, him 30W, me 10W. Now I need a first CW contact ;D

Gil.