ATGP 2013 - Governor Dick Hill - 22 July 2013
Bob Bruninga, WB4APR and Rorie Shaffer NU2J
We got up there in plenty of time this year, around 1115 maybe. Hiked to the top with one Backpack each.
This report includes some overall stuff as well.
Every site was manned and lots of courageous souls in some bad weather.
In your reports, I need to know details. Reliability of VHF both ways. Reliability of UHF both ways. What power levels on both VHF and UHF.
I am convinced we all need front end filters. Even on GD hill that has no other RF at all, our UHF front end was blapping away all day from pagers and all kinds of racket. Even though I could hear the UHF links when the racket would go away, the constant racket drove us crazy.
For next year here are the key points: 1) We are going to use PL on 445.925! 2) We are going to use a good external filter for both VHF and UHF 3) We must get everyone to test their Band A and band B sensitivity.
Remember, I had one radio that had 10 dB loss of performance one year on one band, and this year, MDMTNS had the same problem. Maybe Camelback also had a deaf receiver on VHF. WHen he switched bands finally and GD hill upped to 50W my packets were finally being digipeated by Camelback-9. The log jam was open!
But then found out that 15, 14 and maybe more had closed up shop. So donno if any southern packets were heard north of -9 after 1430 when it was starting to work.
The problem with filters is that with the kenwoods, we will need a dual band filer but that has a single connector input and a single connector output to a dual band antenna. I dont thing such a thing exists. Maybe I can design one.
ANyway, the reason the filters are so important is that even if you dont hear QRM or see any BUSY signal strength, your fotn end could be quite totally blocked by front end overload… making it appear to be deaf.
We are not used to operating in high RF environments, but on these mountaintops front end rejection is a must to be able to hear the weak ones.
Finally the UHF linked system in PA did not work well. The Baltimore node was down, so I could not test beforehand. Then on site, the Lebanon AND York nodes were down. (Apparently they could hear, but the link did not come up at all). Then the site at Camelback that three of us should have been able to work did not work for me anyway. Finally I could talk to Net control if I shot directly to the one he could hit in NJ! But then I was marginal into that!
Remember, a rig can be 10 or 20 dB down and it “works” on APRS locally because we are usually not listening and/or th e path does not matter because SOMETHING will usually hear us. But we cannot tolerate these losses (whether by bad front ends or by overload).
So even 445.925 did not work for us (after MDMTN gave up his Band B to fix APRS on VHF) and we never heard Camelback on UHF nor had any idea that he could hear us. I thknk Camelback was overloaded on all channels maybe?
Bob, Wb4aPR
Regarding Stoneyman to GSD hill direct packets:
Stonyman was heareding GD Hill reliable with one bar. Note, I put 10 Watts to the Maryland Mountains because that was more than enough. At some point I move my antenna and upped the power to 50 Watts so AO-5 could hear me. This was overkill for Maryland Mountains.
So I was ten watts at first then 50 later. This could account for you seeing me with two bars while I saw you with one. - - - - -
John Said:
I get -19 dB from the point where 95% occurs. I’d say more like 65% probability is what I’m seeing with Radio Mobile.
As far as average signal strength goes, however, it says two bars… just like you saw.
I saw a reliable and repeatable 1 bar from you so we were pretty well symmetrical. In fact once things settled in, south bound packets got into a rhythm of weak packet (from GDHill), booming packet (MMtns), digipeat from me, and then one more packet heard (I guess from AO MTN.)
John
I’ll need to look at KD6AKC’s log again to see if I ever decoded you straight.
On Mon, Jul 22, 2013 at 11:11 AM, Bob Bruninga bruninga@usna.edu wrote:
John, just curious what the link looks like from Stonyman to GD hill, since I heard them at 2 bars and decoded some of their packets. I don't plan on skipping MDMTN, but just curious what your LINK calculator gives for this link for comparison to my actual results.
Bob. WB4APR
Rorie’s Report:
Bob covered many of the points from GDHill -I would add the following;
Check the gear in your go kit, the team and success depends on this- As example I heard one station of UHF talking of issues with coax - It is basic enough, but takes a beating - treat it right when coiling and don’t stress connectors.
Solar panels will keep a top up charge level on batteries during the event and allow you to carry less lead to the site - We had 2 7ah and 15ah or so in our packs for the assault up GDHill - all were placed in service through the event and capacity remained.
If you are using a Comet or Diamond Dual or TriBand Collinear design - set it up in your yard and sweep it with a MFJ Antenna analyzer beforehand. The sectional design and tiny capacitors are subject to stresses and points of failure. If you are hearing on one band and not another - could be the or part of the cause.
The A - B band issue dropped in on Bob and I on GDHill in the past - This was how we thought to trouble shoot the MDMTNS station - Point is that we should know our radios - The default side being A for TNC is only a menu option away to switch to B. Just remember to switch the frequency as we use a non standard APRS freq during ATGP to minimize collisions with normal APRS traffic.
If you have an IPad or SmartPhone - bring it up the mountain and use it for checking the Yahoo group for info - monitoring the national APRS network - Checking KWood Tech manuals or even Tweeting. I used my smartphone as a local hot spot and ran APRS software and websites on the IPad to check and support our trouble shooting of the ATGP as we went.
Finally bring along ARRL handouts - We had dozens of hikers checking us out and asking plenty of questions. The sounds of packets on the radio allowed me to explain that we were doing and how HAM radio was an important part of the national communication infrastructure. Several visitors identified themselves as “Preppers” or mentioned a family member or neighbor that was a HAM.
Emphasize the modern computer / digital functions and the fact that we talk to the astronauts in the ISS and that we have our own satellites to use. These points strike the imagination and dispel any other images of well… Bob mentioned to one visitor that getting your initial FCC license is as easy as a drivers license test. That sounded great to me so I added it to the elevator pitch !
Simple enough to get the handouts - ARRL Store will ship up to 25 of each type with any order - So when you order your Field Day T-Shirt or Hat - Add the handouts to your cart for free! People seemed to like the 22 Things You Can Do with Amateur Radio - We Do That with Amateur Radio and HAM Radio Getting the Message Though for your family and community.
73 NJ3U Rory