This is true … there’s no denying it. They are all “rubber-stamp” QSOs. It can be a good way to build up your DXCC score on QRP, though.
73,
Walt (G3NYY)
I think digimodes and QRP became associated because they made QSO possible with low powers than were impossible with SSB at the same power. Because you could achieve nice things at QRP-ish levels people thought you had to run them at QRP-ish levels. Not really true. But for many modes, you need to de-rate your transmitter or it will melt, ham radios are not designed for high duty cycle high power operation.
Some digital modes are constant envelope so the output stage does not have to be linear. All MFSK modes are like this (MFSK, Olivia, Domino, THROB, WSJT modes). This is why you can make little TX’s for WSPR that have a simple, single device PA in class C for a few hundred mW and it works. PSK modes need very linear amplification. That means you should not consider running the average amateur 100W on PSK at more than 25W.
Ed,
5.3 mhz resonance would be obtained by adding tails to the 40m dipole, the length required is approximately 3.4m on each side. Do it using those nice gold pins you found and you’ll then have a linked dipole capable of whatever it was before, plus 60m.
If you also make up similar tails of 10m, you would give the same antenna coverage of 80m. Or add the 60m tails and add 6.6m to those to get 80m resonance. Whatever you think you will use.
Some tailoring of length may be required to find resonance on your preferred mid band frequency. Make them a bit longer, say 10 cm, then check the swr curve.
73 Andrew VK1DA/VK2UH
Hi Andrew - That’s what I have planned.
I already have the 80m sections (I bought the 80/40/30/20m band hopper originally), which incidentally are just over 9 metres long, not 10 metres. I have them removed at the moment as up until now I have not needed them. I still have plenty of the 2mm gold plated RC power connectors as you say, so I will make up the 60m extensions a little longer than needed and trim back based on my readings on the antenna analyser.
I could also fold back and then cut the existing 80m sections at the 60m point and add the connectors but then I would also need to add a strengthening piece and for the weight of the wire I’ll be using, I think I’ll keep separate 60 and 80m sections at least to start with, even if this means a bit longer delay in switching bands.
73 Ed.
To get back to this subject. I’m happy that these modern, super cheap Windows tablets are good enough for JT modes. Mine was £49 and is about as low-spec as you can go. 1GB RAM, 16GB Flash and Win8. The important point is it has quite a fast CPU, an Atom Z3735F. It has no difficult running WSJT-X and decoding in the 12sec window after TX stops.
In addition to the tablet, I needed a USB sound card. These tablets all use the same design and the sound input hardware is not suitable for WSJT-X. 48kHz sampling is needed. I bought a USB soundcard which was £0.99 inc P&P from China and works fine. Also a USB OTG cable is needed to connect the USB soundcard to the tablet. This was £1.50, I plan to use 30m with FT817 for some data mode operations but also try 80m. For that I have resurrected my NJ-QRP PSK Warbler 80 radio that runs about 2W on 3.58MHz. I’ve still to concoct an antenna for 80m, I’m not decided yet on what to use.
This picture shows the hardware, PSK Warbler, tablet, finger dobber, USB sound card and OTG cable. The radio will be in a box in a few days from now.
I’ll be taking this out a bit later in the year when there is more light and hence time available on a summit for experimenting. The only problem I see is getting the time set accurately. Experiments suggest the clock is accurate enough if it is synchronised before setting off. The drift whilst the tablet is sleeping for a few hours before being needed is acceptable.
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For the uninitiated, USB OTG means “USB On the Go”. I had never heard of it before until it was mentioned by the Master of 3-letter Acronyms. 
With regard to the timing accuracy required by JT65, my experience has shown that the mode can usually cope with timing errors of up to +/- 2.5 seconds … maybe even 3 seconds at a stretch. So it is not as critical as most of the documentation would indicate. The built-in clock in most modern PCs and tablets can manage to maintain this degree of accuracy for several hours.
73,
Walt (G3NYY)
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sad story, I recently tested JT on a new Mac with a hefty price tag more than twice my little car (7700!!) and the clock drifts around 1.5sec with every sleep and 0.2sec in a couple of hours of normal use!!!
Never had this before!
I have constantly a terminal open with ‘ntpdate’ ready to run.
The time may drift but look at the rounded corners and how thin it is. These features and the courageous removal of the 3.5mm headphone jack come at a price.
As Steve Jobs would say “You’re holding it wrong!”.
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heheh 
True!
This particular one looks like a glorified trashcan (MacPro)
Even the PCB routing follows a pattern though 
who cares about a couple of minutes of drift!
Steve wanted computers to be like toasters. He hasn’t come inside the house yet if they look like trash cans.
Samsung tried that with their phones, but it wasn’t popular 
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Yet it was the pilot’s iPhone that caused the fire on the EgyptAir flight 804 that crashed.
That’s good to know. I can see the procedure for a data activation to include putting the tablet on charge the night before and syncing the time in the morning before hibernating it for the trip to the summit. It shouldn’t need anything else more that turning on and connecting up.
We shall see…
I’d guess that temperature change might influence the local clock accuracy, though that would be less of an issue for summer activations…a fridge test perhaps? I don’t have a tablet or fridge to hand at present, or I’d try it…
If you have a GPS that is able to be connected to your tablet, you could use that to set the PC clock?
Yes, you can but you need to set the time manually. On the tablet I’ll be using the problem here is the rubbish resolution of the touch panel and the inherent crapness of Win8 UI. You end up stabbing about and generally end up getting frustrated. It will be easier to let the tablet sync via ntp when at home. I could set it by my wristwatch too. I bought it in October 2011 and recently reset the time this January for the 1st time since I bought it as it had gained just over 30 secs in 62months. Or 0.5secs / month! Still a manual process though.
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That is a very practical solution, especially if your wristwatch - like mine - is permanently locked to a long-wave time standard radio station (Anthorn, Cumbria or Mainflingen, Germany). You could re-start your tablet clock by tapping on your tablet just as the second hand on your watch ticks to the exact minute.
Now, if somebody came up with an OTG cable to connect your radio-controlled watch to your tablet …
73,
Walt (G3NYY)
My watch isn’t radio controlled though. It’s just accurate… one of the reasons I bought that particular model.
Agreed! I was thinking more of a backup plan for field use in case M$, or my chinese tablet, threw me a curve ball. I could then connect my Garmin GPS to the USB port on my tablet and use software to set the time from GPS. It looks like NMEA protocol is limited to 1 second accuracy, which is a shame, but close enough. There seem to be a plethora of programs that will accomplish this. The first I found was What is the GPS Clock? | GPS Timing | TimeTools Ltd. I also seem to remember that you could do this through a menu item in Garmin’s mapsource product. I have no idea what accuracy is provided through Garmin’s proprietary protocol.
Perhaps manual setting would be easy and accurate enough!
So don’t use the GUI. You can set the date/time from PowerShell using the Set-Date cmdlet. A nice feature is the -adjust parameter which lets you alter the clock by a specific amount (so it doesn’t matter exactly when it runs).
All sorts of things in Windows which have awful GUIs can be scripted in PowerShell.
Martyn M1MAJ