Over the last couple of weeks, I've started participating in a little round table on 80m at 5 AM. Yikes. These group of guys are outstanding CW operators and all working on honing in on their high speed, or QRQ, operating. The average speed is in the 40-50 wpm range depending on who is there and conditions, though pretty much everyone is running (well) over 100w so conditions don't usually have much impact! I'll admit, the last few years of inactivity mixed with the intermittent keyboard-sent contests, my sending has suffered immensely. Yes, I can probably manage quick fills in a contest at 35wpm but even though I'm close to copying ragchew QSOs at 40wpm, I can't send over an extended period more than 30wpm without errors. It is a humbling and frustrating experience to be among such great ops and still feel like a complete LID! They are all very accommodating though and willing to withstand the poor fist while I improve, which is honorable.
My station has been performing very well through all of this though which is a great feeling. There has been little RFI to speak of and I've become used to relatively comfortable operations. (save the computer taking a dump on me but that's not related to ham radio) With that said, I am always looking for ways to improve the station (plus it gives me something to strive for, which is always good in life). Based on recommendation from a friend, I figured I'd try to get an antenna resonant on 60m. I used to work on 60m a bit from Iowa but it's been years since I have had any interest or reason to check it out. With its "unusual" propagation characteristics, it might be a nice change of pace from the other "low" band operations I'm used to. The Gap Titan is not resonant anywhere near 5.3 MHz so I was left with figuring out something on the inverted L for now. The inverted L is cut for 80m and does a pretty good job there but to get from 3.5MHz to 5.3MHz I'd need to add some capacitance to make the antenna look shorter. Luckily I picked up a homebrew tuner some years back at a hamfest so I had a couple of open air tuning capacitors at my disposal to do the job. I rigged up some hokey wiring and hooked it up and was able to tune a nice null a few places along the coil with the capacitor in series. It was interesting to see how I could pick different spots of resonance and get different network Q, showing a variety of usable bandwidths. I decided to pick a lower Q option so I could get the whole 60m band, and back at the operating position, the SWR stays below 1.5:1 across the whole band. Now I can operate 160, 80, and 60 meters on that antenna without much trouble. Just a few jumpers to move around. I would love to make it remote switching but that's a job for another day.
Next little project was to do some work on the Gap. My and I had a little spat regarding the beauty of my antennas (you can guess which side she comes down on) and I made a private promise to help the situation a bit. The Gap has a wire loop on the bottom part that serves as a counterpoise for 40m as well as part of the 10m element and it happens that the mast I chose for installing it was a hair too short - ok it's about a foot too short if we're being honest - to put the loop above head level. This means when walking around the pool deck, one has to duck to not hit the loop; a scenario that is less than ideal for obvious reasons. As it turns out, the shape of the loop isn't really important for operation on 40m, and at least one other ham has modified his antenna to allow for a more conventional radial in place of the loop due to similar constraints. So to help pad the concerns of the XYL, I set out to do just that. I removed the spreaders and ran a counterpoise along the top of the fence in the NE direction and pruned for a good match on 40m. Luckily I was able to find one not unlike the original match without affecting the matches on the other bands! So now I have a loop-less Gap Titan, and time will tell if it will cause any degradation in performance on 40 (or other bands).
Remember the part about the QRQ CW net in the mornings? Well that high speed, QSK operation has made it really obvious the most critical limitation of the TS-590: Relay based T/R switching. You may recall I noted this way back when I did the side by side comparison between these radios and nothing has changed in that regard. I still think the TS-590S and SG are some of the best deals in radio, especially considering the 2nd hand market for the 590S is down BELOW $700!!! It makes the value proposition against the K3 very difficult. However... if silent and smooth QSK is your goal, there is simply no match for an Elecraft radio (well maybe Ten Tec but lets not go there mkay?).... I think you can see where this is going! Upon introduction of my W6LVP receive antenna loop, the TS-590 now has TWO relays clacking away and at 50 WPM it can be quite a racket. I did make a considerable improvement in this by covering both relays with blue-tack putty (the stuff you use to hold up posters from the office supplies), but both are still quite noticeable even when wearing headphones. Those of you who know me well know I'm a real stickler for noisy stuff like this so it's just hard for me to ignore. Which has brought me to the conclusion that I have to start my journey back to the Elecraft lineup, and perhaps my timing could not be better. It just so happens that my friend N5EIL is in the process of upgrading his remote station and reducing the stack of radios he has at home and among them is a K3/10 with the sub-receiver installed. Neil made me an offer I simply cannot refuse and will let me "hold on" to the K3 for him on the pretense that I buy the 100w PA. Some time down the road we'll decide if I want to buy the whole radio from him or if he'll buy the PA from me. The only drawback is if I decide to let him have it back, I'll be stuck with my only radio being my FT-817, and I think we all know that's a non-starter! So the reality is, I'm going to end up buying the radio from him soon enough and I'll be back in the family! Someone get the Kool-Aid mix!
Hi TJ. I am curious with the LC network on the inverted-L if your are finding you only have to change the L tap between 80 and 160. It sounds like you also have a variable cap, but wondering if you are leaving that stationary. How long is the wire? -Scott, KX9RTReplyDelete
Hey Scott, Yes just have to add inductance in series to resonate on 160. I did add some parallel capacitance on 80 to get the match down a bit which had little impact on the 160m resonance. On 60m the capacitance is in series. I used a variable cap just because it was convenient - I don't have a vector antenna analyzer so I can't calculate the exact value before hand (I kind of managed it with the caps I added on 80m but it was still guess n check kind of design). The capacitor is "switched out" on 160/80 by way of different jumpers. I'll have to take a picture and add it to this post. I'm not sure how long the wire is, I don't remember measuring it honestly. I may have started with a 1/4 wave wire on 80 but I trimmed a lot to get a match so I'm not sure.I may be able to get a real measurement soon - We're doing some work in the yard where my radials are so the antenna may have to come down temporarily. Thanks for reading!Delete
That's a might fine tuner! Really though, that's pretty fun. I was thinking of a remote tuner on my 160m inverted L to give me some other band options and more flexibility for the edges of 160.ReplyDelete