More Problems: Update

After some further reading at work and some continued thought, I worked on the SteppIR when I got home. I checked the numbers on 40M and 80M, since those will be the two bands I will be using the vertical for during SS. The hex beam will be the main antenna for 10/15/20M during the weekend run.

Using information from the SteppIR Yahoo Group I was able to lower the SWR on 30M (10.125) to about 1.6. 40M seems to be no better than an SWR of 1.8. Why? I don’t know, I can assume it is due to surrounding objects in its field. 80M on the other hand seems rock solid at 1.2 SWR at 3.500 and 1.1 at 3.800. So we will see if that holds true tonight during the practice round, which will mainly be on 40 and 80M.

The amp seems to have come back online nicely. Maybe it was more operator problems than technical problems, I don’t know. I still need a 2kW dummy load so I can actually tune the amp to the hex beam and get some better settings. The settings I am currently using were the ones shipped to me from N4UQ when he cleaned up my Alpha.

I’ll keep my fingers crossed as we race towards the start of the practice round tonight. I will be running N3FJP’s logger for Sweepstakes (v4.5). I was planning on using it during SS CW, but could not give up Win-Test. Since I don’t have a voice recorder, I could be hoarse by the end of the weekend.

More Problems

It seems there are a number of issues I am facing as we rapidly approach the ARRL Sweepstakes SSB. First, the lack of output power from the Alpha 76PA. Second, the reflected power as recorded with the Bird 43 or the meter on the Alpha 76, which has been recorded as high as 500w! Third a poor mismatch between feed line and antenna. Lastly, I have been seeing an excessively high SWR on the SteppIR BigIR.

First order of business today will be to modify the element length of 40 and 80M on the SteppIR. I have been reading previous threads on the SteppIR Yahoo Group and have a few things to try. With any luck I should be able to get the SWR of 40M (7.100) down to 1.3-1.5:1 by days end. If not, I will go back and consult the hams on the Yahoo Group for further direction.

It was mentioned in one post to use a line isolator to reduce common mode currents on the coax. So, today I ordered an AS-50-LI, a 50 ohm line isolator from Array Solutions. I must give Bob some serious props. I asked for next day shipping and he said he was out of stock. I told him I was hoping to have it in line for Sweepstakes, at which point he said he would get one built. Talk about customer service. Array Solutions, outstanding! So I will place the line isolator in the shack, use a jumper from the transmitter to the line isolator then the feed line to the BigIR.

The line isolator is not fixing the problem, but more like masking a known issue. I have yet to pinpoint the problems with the Alpha 76PA. RTTY seems to do fine putting out about 500w, with about 200w reflected back. CW was not really that good a few weeks back during SS and in my phone testing the past few days, it is all I can do to get 300w out.

*sigh* With any luck I might get one of the problems resolved before the contest. Hopefully the line isolator proves worthy and limits the reflected power enough to operate without causing issues with the AT&T gateway modem. That is my main concern. It is more than possible to work SS with only 100w. Hell, I would be happy with 150w! Since I have a nice amp, I would like to use the legal limit (if needed).