Help required from mountain goats !

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G7JTT
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Joined: Fri Jun 10, 2016 5:05 pm

Help required from mountain goats !

Post by G7JTT » Mon Jul 13, 2020 7:04 am

Morning all,

I tried a little backpack DATV portable yesterday, with what I thought was very minimal equipment. The thing is it still weighed a ton, so how do you guys that do SOTA and alike keep the weight down ?

My Portsdown in the pelican style case has 6x18650 in so that has its own power, but my 23cm PA would soon drain this so I use a 19ah SLA battery. The mast at present is some old steal tent poles so could change these to aluminium or fibreglass I suppose?

The other thing is PA power, just how little would be practical with DATV? Not looking to smash DX records, but hopefully take advantage of high spots not reachable be car portable. Not that there are many here on the South coast, but thinking ahead when holidays are next being planned it may be worth looking at the terrain first 😉

All best and stay safe John G7JTT

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i2NDT
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Re: Help required from mountain goats !

Post by i2NDT » Mon Jul 13, 2020 8:14 am

and you can also enjoy fresh and free milk!!!

https://www.youtube.com/watch?v=sSjSzInUhjU
i2NDT Claudio
Dalmine, Italia

G7JTT
Posts: 202
Joined: Fri Jun 10, 2016 5:05 pm

Re: Help required from mountain goats !

Post by G7JTT » Mon Jul 13, 2020 1:48 pm

😂😂😂 Very good Claudio not a fan of goats milk but love goats cheese 👍 I used to own a goat many years ago but he wouldn't have been as well behaved as the goats in the video. We used to take him for walks untill an out break of foot and mouth in the UK meant lock down for all split hoofed animals, then the rules changed and it wasn't allowed anymore. I have a video of my youngest with his cycle helmet on playing head buts with the goat somewhere hi.

All best John

M0YDH
Posts: 210
Joined: Sat Dec 31, 2016 5:59 pm

Re: Help required from mountain goats !

Post by M0YDH » Mon Jul 13, 2020 7:01 pm

Hello John
Some random jottings follow. After over 220 SOTA activation and becoming a SOTA mountain goat , I can say that it's about pack weight. Mine has been around 28 lb constantly. I play a trade off between weather conditions, how high and how far against radio hobby equipment. 1 pointer in Shropshire would permit a FT857D, LiPo batteries and a lot of wire antenna with less stuff for taking care of me. An 8 pointer in the Lake District or North Wales needs more clothing, drinks and food so there's room for a handheld and 2m dipole. Line of sight from 800m ASL is rather good.

There's no ATV category in SOTA as far as I know. Perhaps the club could ask the management team at SOTA nicely for one? Our clubmates in Cumbria have done 6cm FM ATV on SOTA summits and managed a summit 2 summit. All on 1 pointer summits. Well done there.
You're going to need a barrow, hand cart or mountain bike with panniers for the kind of mass that you're using. An ex-infantry soldier would do. All great until the first stile or tight gate! We wish an activator a safe descent because we know how vulnerable are ankles. I've some horrid injuries from 2009 on Moel y Golfa so know this first hand. :? Is 70cm the sweet spot for DATV in terms of amplifier power and mass ? One of those amp kits off Ali Express that have no instructions might do if Jim G7NTG has worked out what to do? One of my 70cm beams is from B&Q - stockists of 25mm electrical plastic conduit, aluminium rod and tube and PVC tube (dipole centre). It splits in two with a sleeve joint. 22mm wastewater pipe fits inside 25mm conduit. About 200 grams too. My 2m and 23cm beams are B and Q too.
When I attempt SOTA DATV I am going with my activation partner Alastair M0TYM who does a good impersonation of a Sherpa. He once carried 2 SLABs up Aran Fawddwy and only found out at the top. We didn’t use the batteries nor the HF radio cos it was bloody awful weather. I fancy trying to activate tv on Cadair Berwyn after many smaller hills practice. Pipe dreams.
Ray M0DHP does SOTA and DATV - separately - on the South Downs so might be a handy collaborator. Butser hill to Chactonbury Ring S2S?
This is a tricky challenge. Well done so far.
73
David M0YDH

G7JTT
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Re: Help required from mountain goats !

Post by G7JTT » Mon Jul 13, 2020 8:05 pm

Thanks David lots to think about and yes I think the band will play a big part in what is needed ! Oh and one thing I'm never go'na make a mountain goat status lol, it's more a case of trying to take advantage of the few high spots round here that you can't drive to the top of. Plus trying to keep the kit to a minimum, so I can just use it with out spending hours loading the car up and even longer unloading and setting up.

All best John

radiogareth
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Re: Help required from mountain goats !

Post by radiogareth » Tue Jul 14, 2020 7:45 am

A lot of the above has crossed my mind, triggered by the early days of SOTA which caught my interest. There are only a few summits in the SE, many of them with easy access from a nearby carpark. Over the years I've developed/built a variety of stuff that IMHO addresses the problems posed by portable ops...but largely unused in anger. It is my intention to 'get out more' and actually use the kit I have built. FWIW here are some of my 'solutions'....
Battery power - battery tech has moved on a lot from SLAs - the RC flyers hobby has spawned some very good LiPo batteries (like anything, understand what you are doing and all will be well). For current draw and light weight they can't be beaten. Due to the massive market, they are cheap too.
LiFePo are a 'less fussy' alternative, still offering great power density and increasingly popular for golf carts and mobility scooters. (£££'s though).
Big laptop packs I investigated for SOTA use via airline travel - you are limited to under 100W/hr packs and rather than be faced with 'you can't take that with you Sir' I checked the CAA rules about what you can take. OEM laptop batteries are not things that look like bombs. I found info on how to 'turn on' the packs online, built a connector and tested a couple of 98W/Hr toshiba packs. They will tolerate up to a 8 amp draw and delivered over 7.5A/Hr at lower draws. Recharge from a RC 'all-types' charger seems to work well. This pack would power a small amp and portsdown for a good time.
I built some fishing pole yagis for 2m - 6 element at 5m AGL. It worked well so I moved on to a 12 element ZL special, based on a 10m fishing pole. All lightweight and backpackable and LOTS of gain. A similar solution for 70cms would also be entirely possible, its on my 'to-do' list.
Given how full-feature a Portsdown is, adding just a Picam and a Lime mini with a 70cms brick amp (in a recent CQTV) and a beam is should be possible, with care it probably weighs less than a FT817. The MRF100 datasheets/AN's shows a really minimal board design for a 144 MHz amp and other than needing a step-up from 12-50V would easily reach / exceed DATV ERP limits with a small beam. Also on my to-do list.
Comments re ankle noted - I took a lot of this gear on holiday to Lanzarote Dec 2018 with my son, who went to cycle. As I walked up an unactivated volcanic cone, on my own, I was thinking....this really isn't a good idea....so I was VERY careful. Got to the summit, set up, worked nobody on 20m, but all the kit worked as planned.
Pictures and more info if anyone is remotely interested - message me and we can progress to email so I don't have to resize the pictures....
Gareth

G7JTT
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Re: Help required from mountain goats !

Post by G7JTT » Tue Jul 14, 2020 6:51 pm

Hi Gareth did look at LiPo batteries as an alternative, will have to look into that further. The Portsdown already runs from recovered laptop batteries. Parked up at work one day to find a smashed up laptop in the car park, found the battery pack intact and recovered the batteries 👍. As to bands 70cm is most likely the band I'll go with although 23cm does have the advantage of smaller higher gain Yagi's. I'll most likely build a long Yagi that collapses and maybe drill the boom like people do with the arrow sat antenna's. As to PA's I'm thinking that a smaller lighter heatsink with some sort of forced air cooler with big fans ! Maybe one of these big CPU heatsink and fan, with the PA fitted directly to the heatsink ? And yes if you could send details of your Yagi would be interested, mycall@yahoo.com.

Cheers John

M0YDH
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Joined: Sat Dec 31, 2016 5:59 pm

Re: Help required from mountain goats !

Post by M0YDH » Sat Aug 22, 2020 2:39 pm

Seriously I've gone into bat over on the SOTA reflector asking for ATV to be a recognised mode in Summits on the Air. https://reflector.sota.org.uk/t/amateur ... mits/23644
It's not going to be easy and I suspect the brigade who buy their station retail aren't sympathetic.
The brief answer without a salutation from database admin chief Andy MM0FMF "For the time being DATV is Data and analogue ATV is Other." This doesn't come across as very friendly. :o
If you intend to operate from SOTA summits in say G/SE, G/LD or wherever using lightweight ATV please add your voice to this topic.
73 and a safe descent
David M0YDH

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