Got myself in a bit of a worry. I have an Ft 817ND and a Buddystick. Can I use this combination without an ATU? Iv’e just been reading so many stories about blown finals and would appreciate some advice from someone.
Thanks
Fred
2M0COT
In reply to MM6ALZ:
Here is a link for the manual http://lib.store.yahoo.net/lib/buddipole/buddistick2008.pdf
And the manufacturers site The Buddipole - HF portable dipole antenna system
You have the 817ND which is the same model as i own, now I’m no expert but to what i can make out it is the original FT817 that i hear had issues with high SWR and blowing finals.
I have owned my 817ND for a little over 3 years now and i bought it used, i sometimes see VHSWR when tuning and have had no problems. A further note is i have always monitored the SWR via the built in meter and my personal preference is nothing over 3 bars showing. Hope that helps. Sean M0GIA
In reply to MM6ALZ:
Can I use this combination without an ATU?
Yes, just follow the tuning guide in the manufacturer’s instructions.
Andy
MM0FMF
In reply to MM6ALZ: Yes. As has been said, the 817ND does not seem to be as prone to blown finals as the original version. It makes sense to do your initial tuning on the lowest power setting in any case, then increase the power once you can’t see any SWR bars on the low setting.
In reply to MM6ALZ:
Hello Fred
The buddistick can be used without ATU with any transceiver but it requires a rigorous adjustment of the antenna. We must identify the buddistick settings, giving the strand that forms the ground plane. Then a reading of the SWR on the 817 is sufficient.
best regards
f5nep Lionel
In reply to G4ILO:
does not seem to be as prone to blown finals as the original version
Perspective time.
a) How many hundreds of thousands of 817s are there in the world?
b) How many have the old PA board which is the allegedly fragile PA?
c) How many old PAs have failed when subject to gentle use?
d) How many old PAs have failed due to bad loads/misuse?
The answers are a) very, very many, b) a lot, c) almost none, d) not a lot
The failure rates can be measured in the fractions of a percent.
This is a typical internet phenomenon. Some people (nobody knows how many, not a lot) have had a problem. Some people wrote about their problems. More people read about the few having problems and write that you can have problems. More and more people read about thew few problems and suddenly the 817 has a reputation for having a dodgy PA.
Except that these problems nearly always date back to 2002-2004, i.e. 5-7 years ago and the PA board that is meant to be fragile, has been out of production for some time before the ND model was introduced.
So we’re talking about a fraction of a percent of the total 817 population. When you go on to consider that more than many radios, the 817 is more likely to be abused as it is used portable so often, it’s remarkable that so few owners do have problems. My own 817 is an early 2001 model which has been up 120 or so summits never mind used as a signal source for all kinds of experiments and seems to be fine. Many other owners of older 817s on here are in the same boat with no problems.
As you say, it makes sense to tune on lower powers and increase the power when the match is better. Which is how you tune everything, whether it’s a few watts from an 817 or your cough-cough 3kw contest linear.
ISTR a replacement PA board is about £15+vat so even if you are unlucky it’s not the end of the world as you can replace the board yourself.
Andy
MM0FMF
In reply to:
For complete peace of mind then you could use a resistive absorbtion type swr bridge for tuning.
e.g. %PAGE_NAME% - Pacific Antenna
this presents a good load while you are tuning.
Also it might be practically easier to tune this way than to use the swr display on the ft817.
Regards,
Nigel. G6SFP.
In reply to G6SFP: Which reminds me that the Emtech ZM-2 http://emtech.steadynet.com/zm2.shtml is a QRP ATU which has a built in resistive absorption type meter.
In reply to G4ILO:
Many thanks indeed to all those who have replied. Certainly put my mind at rest. If there are any other comments I’d be glad to see them.
73’s
MM6ALZ
In reply to MM6ALZ:
Fred,
i use the buddistick with a 2008 FT-817ND in 50 0dd activations:
…with ATU when I want to set up / change bands quickly (no precise tune on buddistick needed).
…without ATU when I have time / forgot the ATU or it doesn’t work.
I tune as follows: FT817 5W Output, meter set to SWRmeter, while keyed down find minimum approx. SWR display while sliding with te plug along the coil. Then fix cable to coil at this position ± 3 coil turns to find lowest SWR (usually no SWR bar visible at best match). Can match in this way very quickly, but not in rain / snow / sub-zero / high wind - then ATU is convenient.
I prefer to operate on a 1m coax patch cable without ATU: no ATU no loss…
Regards,
Gerd.
In reply to MM6ALZ:
Got myself in a bit of a worry. I have an Ft 817ND and a Buddystick.
Can I use this combination without an ATU?
Sorry for this late post, just want to help you in using buddistick antenna, go to this buddistick settings link http://www.corail.nc/FK8DD/buddistick_setting_up_eng.html
Vy 73’s
Sam
FK8DD
Am I the only one who finds the idea of using a totally useless overpriced piece of junk as an antenna on a QRP rig ludicrous?
By the time you have run out enough counterpoise to make the darn thing actually work you may as well have put up a proper dipole (with or without an ATU) in the first place.
There is always some snake oil salesman selling their “Miracle Antenna” and someone is always ready to buy into the idea.
Regards Steve GW7AAV Sceptic
In reply to GW7AAV:
Steve
i really was sceptic too till i use buddistick for the first time. And till then i can not go back to the wire stuff. Ok i can go around the fact that in most summits we have no trees or anything to raise a “proper” dipole but no fishermen pole can hit how fast you can setup a buddistick (it needs only one counterpoise and have your job done). Yesterday with only 300mw (Rockmite) i almost had a solid QSO with a DL station (“almost” means i lost him on the second round due QSB).
It works, i have not the skills to explain you how it works nor any way to persuade you, you have to try it to understand. I again admit that i was sceptic like you.
best regards
Panos, SV1COX
In reply to SV1COX:
Shortened verticals are simple not efficient antennas, that is a fact. On a motor vehicle we simply have no choice, but at least the metal body of a vehicle acts as a good ground and most of us have had good results from /M operations which might fool a few in to believing a shortened vertical was a good idea for /P operations. If you were to lay out 100 radials cut for the band you are working with your shortened vertical you might just start to approach the efficiency of the antenna mounted on a vehicle, but you are still in negative gain to a dipole. The biggest thing that persuades people these antennas actually work is that they receive fairly well, but using the rubber duck antenna for 2m on the FT-817 it is amazing what you can hear on every band. I was unfortunate enough to get a ‘Miracle Whip’ given to me and I was amazed how well it receives but in tests it transmits less RF than my dummy load. I have built similar antennas to the B~stick in the past, the design is not new or unique and their inefficiencies are well documented as are the “amazing results” some people have had “from time to time”, but they are not an effective antenna for reliable results. They are also seriously over priced for what they are. Anyone thinking that the even more expensive B~pole would be a better bet might like to try making a shortened dipole from two monoband mobile whips first and see just how rubbish that is even compared to the same antennas mounted on a vehicle.
If you have to use a shortened vertical because a summit is too pointy or too crowded for a dipole then good luck, but don’t expect to get a log book full of contacts. If you must use a shortened vertical don’t spend £150 buying one, make one and save £120. Similar designs to the B~stick are out there on the Internet and if you use a wire wound loosely up a 7m fishing pole it will work much better than than the silly little whip the commercial version comes with. You could even build a properly switched loading coil into the same box as a mini tuner for band changes without all that messing about with jumpers.
Sorry Panos but what I can’t understand is why you would build a radio from a kit and then use a commercial antenna. That to me is like climbing a mountain and giving up ten metres from the summit. I am sure you have other antennas and proof of what I say is simply a matter of setting up both and getting comparative reports.
Best regards Steve GW7AAV
In reply to GW7AAV:
Steve,
what’s the loss of a B-Stick as compared to the dipole you actually use say on 7 MHz - any measurements done or data available?
Was interested in the B-Stick loss for some time, maybe you know?
Also please my you point out the literature you mention on the “up and away” antennas? Tnx
Regards,
Gerd.
In reply to GW7AAV and somehow to DF9TS:
hey please we can not convert any discussion here in a debate…
Steve, no one can believe in miracles or “miracle whips” … no one can believe that a coil shortened antenna can be better than a “proper” dipole or a Windom. BUT we speak for SOTA and summits here. And to do “the portable operation thing” on the summits is one part of the story; the other is to get there. And actually you seek only 4 contacts up there, these are the rules of the game… not a log “full” of contacts, just 4 of them.
For that side of view i (through my experience) can declare again that B-stick worth the 95 UK pounds (plus shipping). Ok sometimes working with FT-817 and 5W or with KX-1 and 3.3W it will not give you the QSOs you want on the band you want but definitely will give you the needed QSOs in les than 15 minutes under any prop condx.
I gave a try with long wires and elecraft T1 tuner and under the special conditions on summits i prefer 100% the B-stick. And it is rugged, more rugged than i could make an antenna like that with my machining skills.
On SOTA the story is to go up there and THEN manage at least 4 QSOs on there… After some tests B-stick suit my style perfect (ok we made and will make some tests and changes all the time,(btw be aware that B-stick CAN NOT work with KX-1 with its internal ATU due to returning RF currents on the feed line, so you need to add something like an RF choke on the line -add that to the cost-). And so on… every summit is another story looking your fellows equipment and ant choices & seeking the “perfection”.
Thanks for the info, it was much appreciated.
73, Panos, SV1COX
In reply to DF9TS and SV1COX:
The radiation efficiency of a shortened vertical will be less than 1/3 over a perfect ground. Assuming a 10-ohm ground loss your radiation efficiency drops to around 9%. So with a 100-watt transmitter you will be putting out 9 watts. For an FT-817 running 5-watts that equates to 0.45-watts. For 300mw from the Rockmite that would equate to only 27mw output. With higher ground loss the efficiency can drop below 1%.
First watch this and then tell me you can erect a Buddistick quicker.
Now read this…
http://www.ad5x.com/images/Presentations/AD5XMobileOpsHintsandKinks.pdf
Some more good stuff here…
http://www.ad5x.com/images/Presentations/lowcost.pdf
and other none relevant good stuff on the main site…
http://www.ad5x.com
A good place to start if you still want to make your own is the W3FF Home Page Home of the homebrew “Buddipole”
This document gives some advice on construction… http://www.zr6kmd.za.net/pdf/Homebrew%20PVC%20%20Buddistick%202007.pdf
The Buddistick yahoo group has a lot of info about buying a monkey and getting a brain and maybe where to buy Viagra so is probably best avoided.
However you might like to spend a few hours trawling this site for tasty tip bits…
I could go on for hours posting links but as we say Google is your friend.
Debate is what separates humans from animals. The idea is to get people to do their own research and make their own decisions, rather than being sheep and getting suckered in to buying something that does not suit their needs or indeed do what it says on the tin.
Four contacts! Okay the activator is king and can do what he or she wants but the idea of the rule is that it is a minimum of four. If I knew there was someone setting out to just make four contacts every time I would a) not work them and b) not Spot them and I Spot an awful lot of stations. Whatever the rules say I consider the attitude of ‘four and gone’ to not be in the spirit of SOTA. If you are in bad weather fine get four and get to safety. I usually spend over an hour on each summit and I have spent four hours on one summit using every band from 80m to 23cm. I don’t expect everyone to do that but I do expect them to give the chasers a chance of working them by running as efficient a station as they can muster. If you only have a VHF hand held on a rubber duck that is fair enough but try to run a QRP station using an inefficient antenna on a crowded HF band and I can only wish both activator and chasers good luck because they will need it.
Debate, learn and pass on you findings so other can learn too.
Regards Steve GW7AAV
In reply to GW7AAV:
thanks Steve.
Panos, SV1COX
In reply to GW7AAV:
Steve,
tnx for the links. Yes the buddistick can be put up in less than 2 mins if the parts are prepared on the ground like in the video (just tried: 1:30). In reality it takes abt 5 mins including unpacking from the rucksack.
Experiments we undertook with very short antennas and QRP indicate efficiencies higher than what your reasoning above would allow. This could be due to the models beeing inaccurate for very short antennas - thus my interest in measured data.
Regards,
Gerd.
In reply to DF9TS:
One of the problems with any low mounted antenna you experiment with is it is so much more effected by its surroundings than one in free space (if there was such a thing) and that makes accurate modelling near impossible. Every time you set up in a new location you will get different results. Just add the operator to the mix and just moving your hand to pick up the microphone can violently upset the complex radiation pattern. Field measurements are similar to the problems experienced in Quantum Physics because our intervention to take readings also effects the results we get. In a real life situation on a hill top that could equate to a man with a dog stops for a moment and I can hear you and then when he moves off I can’t.
I have been involved with low power experiments and it is amazing what can be achieved. I have had hand held rubber duck to hand held rubber duck contacts over 100 miles on 23cms FM using 500mw with 5/9 reports both ways and have been on the receiving end of inter-UK (100-250 miles) NVIS (Near Vertical Incidence Skywave)transmissions on 60 metres SSB still perfectly readable down to 1 microwatt so I don’t underestimate what is possible.
To conclude, I think that a linked dipole is fairly efficient, light weight, cheap to make antenna that includes the possibility of NVIS propagation on 80,60 and sometimes 40 meters and that the B~stick is an inefficient, heavy and expensive to buy antenna and that by being vertical is not likely make use of NVIS propagation and because it is out of phase with the majority of receiving antennas is likely to appear even weaker again. There are places short verticals will come into there own, but give the chasers a chance and use a bit more power to try and make up for the antenna, please.
I too would be interested in seeing more measured data if anyone stumbles across anything.
Regards Steve GW7AAV