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| Yaesu FT-817 w/ MFJ 1899T antenna |
Another old post from my wordpress site:
March 28, 2011
My wife and I conveniently had last week off of
school and work for Spring Break, so we were able to do some traveling
and relaxing. My wife brought her sewing machine along to work on a few
projects from the hotel room, but I didn’t bring my radio gear because I
knew I had limited antenna options from inside a hotel room. I have
used speaker wire dipoles with great success but I try not to bother my
wife with those on vacation because she is patient enough with my
variously strung wires around our home. The weather wasn’t exactly balmy
either so I ruled out any outdoor portable work. I decided next time we
travel I would have something capable of operating indoors! I’ve looked
into magnetic loops and while they’re excellent antennas considering
their small size I decided to go with a more conventional and compact
vertical whip antenna.
I ordered a MFJ 1899T from Gigaparts and had it here on my
doorstep in less than week. There’s not much to this antenna and I’m not
convinced that it’s all that sturdy but with a little care I don’t see
it breaking too easily… I hooked it up to the rear PL-259 jack on the
FT-817 with a right angle and BNC adaptor. Using the supplied tuning
guide I tried it on various bands and found that it doesn’t even come
close to the recommended settings - but with a little trial and error
the correct jumper and whip length can be found for minimal SWR. I had
my Par End Fedz hooked up to the front BNC connection so I was able to
readily switch back and forth to compare signal strengths. When tuned
correctly, I was pleasantly surprised to find that the little whip was
very close to the Par antenna. Definitely a little quieter, but not
enough to lose a station unless they were right on the noise floor to
begin with. Even tuned correctly I had couple bars on the SWR meter but
was easily rectified with a 3ft counterpoise attached to the ground
screw on the rear of the FT-817. Now I still hadn’t transmitted with it
yet so I wasn’t setting my hopes to high on this little antenna. I
figured the fastest and easiest way to get some signal reports was to
run it with WSPR, so I set up the software and let it whisper it’s
little whistle into the ether for about 15-20 minutes. Came back to
check on reports and….wow! I had hoped it could at least net a couple
stateside stations but was quite happy to see the little whip chucking
the little signal across the pond into Europe! Here’s the WSPR Map:
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| 20m WSPR w/ MFJ 1899T |
I realize using WSPR is kinda “cheating” because you could
probably go outside, holler your call sign, and with the capabilities of
the software someone in Madagascar would see you on their waterfall…
but I feel it’s a good way to really get a feel of where your signal is
going. I will be doing some more extensive operating with this antenna
in the future but so far so good! I will keep everyone posted on how it
works out… On a side note I’ve been noticing the rear heat sink on the
FT-817 gets quite hot with even minimal use, my FT-817ND barely got warm
even with heavy use…curious….
29 March UPDATE:
This morning I checked into the New Mexico Breakfast Club on 3.939 mhz using the 1899T and 5 watts. It took a couple tries to get through but I was able to get in there none the less… This antenna is pretty slick. In no way will it ever perform as well as a full size antenna and I would never recommend it as a primary antenna but if your traveling or due to size constraints this is the only thing you can fit, it will get your signal out there reasonably well. Last night I did some listening on 40m and there were times when a station was 100% copy on the Par 10/20/40 and then was completely gone when I switched to the 1899T - so in some circumstances it can be quite deaf, but if you’re just having fun and don’t mind missing a few stations here and there it won’t be a bother.
This morning I checked into the New Mexico Breakfast Club on 3.939 mhz using the 1899T and 5 watts. It took a couple tries to get through but I was able to get in there none the less… This antenna is pretty slick. In no way will it ever perform as well as a full size antenna and I would never recommend it as a primary antenna but if your traveling or due to size constraints this is the only thing you can fit, it will get your signal out there reasonably well. Last night I did some listening on 40m and there were times when a station was 100% copy on the Par 10/20/40 and then was completely gone when I switched to the 1899T - so in some circumstances it can be quite deaf, but if you’re just having fun and don’t mind missing a few stations here and there it won’t be a bother.
Last night I also ran some WSPR on 40m. Was happy with the results on that band as well:
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| 40m WSPR w/ MFJ 1899T |
Hello Luke,
ReplyDeleteI have a similar setup but with the Yaesu SCU-17 with CT-62 CAT Rig Control to the FT-817ND. I have ALL the W4RT upgrades to this unit. I have no clue why but I can't seem to get anything useful on HF on this. I can use it for an expensive 2m/70cm unit to local repeaters but that is all. If you have time to comment and help a fellow ham out with settings (as I am new to this unit and the SCU-17 does seem to be controlling the unit correctly), please email me at tateconcepts@gmail.com. Thank you for this information as it is quite helpful. I plan to build a better HF antenna but this is all I have at the moment to work with and surely I am doing something wrong, what I have no clue. For privacy I will send you my callsign via email. 73
Brian, I have used my 817 in a number of SOTA situations. One time, I forgot my antenna but had a bunch of wire. I used a small MFJ wire antenna tuner and some other wire as a counterpoise (IMPORTANT!!) and had contacts all over the US, and a few in Europe. Make sure you use some sort of counterpoise as it is the other half of the antenna! But just keep trying!
ReplyDeleteWhere do you hook up the quarter length counterpoise to the ground or the antenna?
DeleteBrian, I have used my 817 in a number of SOTA situations. One time, I forgot my antenna but had a bunch of wire. I used a small MFJ wire antenna tuner and some other wire as a counterpoise (IMPORTANT!!) and had contacts all over the US, and a few in Europe. Make sure you use some sort of counterpoise as it is the other half of the antenna! But just keep trying!
ReplyDeleteThis comment has been removed by a blog administrator.
ReplyDeleteThis is a great antenna for portable operations and will work best with the counterpoise lengths suggested. I also use it as a travel antenna. Its a compromise but it does work if the bands are in good shape. I made quite a few contacts on 40m from the Dayton Hamvention operating portable out by the fleamarket area . Mark the counterpoise with some orange flag tape so no one trips over it. The CP is best when a few feet off the ground.
ReplyDeleteRead the instructions and use the settings there as a starting point. Also take note that they do not recommend a 1/4 wave counterpoise, but 180/FREQ (mhz) = Counterpoise length in feet. Whip length seems to vary a good bit from the chart. For instance in my case 40M whip length says 47 inches, one inch less than full length, but to achieve good swr, I had to go with about 40 inches on the cw segments. Also note that you can adjust the antenna at any point on the whip...doesn't have to be the top section. Go about an inch at a time and you should see the swr start to dip rather dramatically. Haven't tried to make contacts yet but when properly adjusted receive was very near same levels as my full size dipole, which is pretty impressive. SWR does matter...with a mismatch you will hear almost nothing. You need to make the antenna resonant, not just tune it with an antenna tuner, which makes the transmitter "think" there is a match.
ReplyDelete