Limited SO2R RTTY
This was my stations in Florida from 1995 to 2004. All the stubs and such were located on the
floor below the operating table. I did not have alot of space for my station, this is contained
in a 4 x 7 closet that had bi-fold doors to hide everything.
This was my setup in Melbourne Florida from about 1995 to 2004, then I moved to Fadette Alabama. Don't have the SO2R setup right now. Radios: RADIO-1 (FT-1000D) RADIO-2 (FT-990) Interfaces: two terminal units (this was before sound card decode became so prevalent) One Computer running Writelog, although I am sure that N1MM Logger would work equally as well. Antennas: (all on one 45' tower; a city lot in Melbourne, FL) TH3MKSII, Tribander (used for 10m and 20m only) at 46' DB1015, 10m/15m Duobander (used for 15m only) at 30' fixed due North. 40m Deltaloop with the apex at 42' 80m half sloper at 40' (ran though the middle of the loop) EWE RX Antenna for 80m pointed North only mounted to the fence. Unfortunately I did not have multiple towers with big antennas, or the fancy automation for antenna switches; or band data controllers that supported two radios. I figured there had to be another way, so I decided to setup up a limited SO2R with RADIO-1 for 10m, 20m and 80m, and RADIO-2 for 15m and 40m. With this setup and adding the DB1015 to my existing antennas, I could have two bands covered at any one time and possibly have an option to operate on another band. For example: 1. RADIO-1 on 10m and RADIO-2 on 15m or 40m, chances are that 15m would be the perferred band, but you still would have the option on 40m. 2. RADIO-1 on 20m and RADIO-2 on 15m or 40m, both of these will be good choices early in the day and the other antenna going toward sunset. 3. RADIO-1 on 80m and RADIO-2 on 15m or 40m, 40m will probably be the best option with 80m. 4. RADIO-2 on 15m and RADIO-1 on 10m or 20m or 80m. 10m or 20m will be two very good options that work well with 15m. 5. etc, etc. perhaps you see how it would go. Either radio can be used to RUN or S&P. Since I am predominantly righthanded I found it easier to RUN with the radio on the right side, but I did learned to be able to tune with either hand. It did get a little busy with the mouse and tuning with the right hand, but you can work through it. Really the only limitation with this setup was not being able swap the radios. To switch focus for 15m or 40m to the RADIO-1 or 10m, 20m or 80m to RADIO-2, it don't work, you have to commit one radio to 15m and 40m and the other radio to 10m, 20m and 80m. It would have been nice to have RADIO-2 on 40m and check 15m with the other radio sometimes especially since one of my radios was capable of 150 watts output. This was why I picked 10m, 20m (because it is a bread and butter band) and 80m (because it was so noisey) for the FT1000D so that I could run a 150 watts on those bands. I figured that 15m and 40m would be OK at 75 watts or less. Not having this ability to switch focus did not seriously impacted my scores. hiImportant:
What makes this work is the coax stub system outlined on K1TTT website. Dave's website does a real good job describing how to implement the stubs. So you might think that the coax and connectors would be pretty costly, well if you shop around for the connectors and coax then you can save a bit of money. I often got the coax for the stubs from left over pieces that were too short for regular tower runs. When I replaced a few runs, I used that coax for the stubs. Another Ham was moving into an antenna restricted neighborhood and he gave me some coax. I did not buy any coax to make stubs. NOTE: I would say that the coax needs to be in good serviceable conditions, if it is oxidized on the shield then it is probably not good for this use. For the most part I really never had much of a problem with inter- station interference because the stubs did a great job. But there were a couple of things that had to be watched for and be careful when tuning the other bands. For example: 1. When operating on 40m, I had to be aware of the second harmonic on 20m. For example, if I was CQing on 7040, there would be pretty good signal present at 14080 (plus or minus), so I would have to be careful not to tune in that area with RADIO-1. Moving down or up from 14080 a couple of kHz would be enough to make the radios happy with each other and me comfortable with the radios working in those areas. This was the primary problem area, because the direct multiple of a harmonic frequency on 40m could definitely land in the 20m RTTY band. 2. Additionally there were occasional combinations say around 14050 you could produce a second harmonic at 28100. This did not happen often because one seldom gets that low on 20m or that high on 10m but you could. This may have changed now and in the future with the increase in RTTY activity level and Cycle 24 bring 10m alive. But is it just a matter of being aware that this might occur and adjusting for it. If you watched out for these you would not have any problem. I never had a problem with hurting the front end of either of my radios. So what about the Results? Personally, I really could not spend enough time at it to really get good at it. WORK seemed to always get in the way of my favorite contest, RTTY RU and there were several years that I did not get to participate at all because of work. I did get to use this setup a few times, and I really think it improved my QSO numbers by about 20%. Prior to the limited SO2R setup I would be lucky to get 800 to 900 Qs in RU and boredom would set in towards the end of the contest, because there was no one to work, I would have a hard time staying in the seat. After I got this setup, I was able to get 1000 to 1200+ Qs and my personal activity in the contest was increased--I enjoyed it more. It is easier to stay in the chair when you have stations to work... hi So how simple could this be? I really think that someone could have an SO2R station with a tribander, 40m inverted vee and 80m inverted vee and/or a second vertical antenna that would cover several bands; or two verticals; or all wire antennas. The object would be to have atleast one (or more) band that you could give to a second radio. BTW I have heard guys for years talking about "backup radios" why not use that for your second radio. Of course you need the appropriate stubs; and one could be in business (so to say). Would I recommend it? Sure! You can have more fun operating in these events, even if you just get in for a few hours. Making more contacts has got to be more fun! Work at your own pace. At first, I found that I could not do SO2R at the beginning of a contest, way to much activity in the beginning of a contest. Heck I am not to sure that I can do it now, but it is OK to let the second radio sit idle and then when activity on the main radio slowed down a bit and/or especially on Sunday, it becomes easier to think about the second radio. OK, hopefully this will help someone that is interested in RTTY SO2R, but concerned whether it would fix in their shack or on their lot and perhaps the cost. If you already have two radios then perhaps the cost becomes minimal after that. cul es 73 Jim/KC4HW