It's been a while since I've updated my ham radio page. The last year has been a significant time of change for me. I recently retired from employment and that has given me more time to participate in amateur radio and other activities. Similar to other retirees, I sometimes wonder how I had time to work. It seems I have no shortage of projects and things I need to do! Since my last post, I completed the Yagi antenna installation on my tower and it has been working very well. The HF antennas are working well and I recently confirmed enough HF DX contacts to qualify for DXCC. I now have 114+ countries confirmed on the ARRL's logbook of the world. My long term goal is to achieve DXCC honor roll using only LOTW confirmations. Currently, I have been focused on working the ARRL Centennial portable operations as a year long goal of achieving worked all states (WAS) using only ARRL portable contacts.
During the past several months, I have completed a few ham radio projects that have been on my “to do” list. First, I renovated my workshop that is located in another area of my home to make it more suitable to perform tasks on ham radio/electronic projects. It's in that area that I build and repair my ham radio equipment. During the period, I also built additional shelving for my operating desk, and refined the switching matrix for my station. The station is now much more operator friendly and the switching matrix is simplified as well.
I own a Kenwood TS-830S Hybrid HF and use a Kenwood DFC-230 solid state frequency controller to stabilize the VFO. However, recently the DFC-230 began to act in an erratic manner. Due to the age of the DFC-230, I thought it would be advisable to begin with replacing all of the capacitors. Apparently, some of the capacitors were defective, because the DFC-230 began to function normally once it was recapped. Total cost was around $12.00.
Another project I completed was to replace the capacitors in a 1947 Philco Audio/RF Signal Generator. I had been looking for a signal generator, and this one was offered to me at a very good price by my friend Reid W2HU. The metal work quality is outstanding, and certainly surpasses anything produced today.
Recently, I also added several new transceivers and a vintage amplifier to the station. The amplifier is a Drake L-4B to use as a companion to my Kenwood TS-830S. The L-4B is in very good physical condition. When purchased, the inspection tag was still attached to the amplifier, and showed a build date of June 6, 1977. As a statement to the durability of the Eimac 3-500Z tubes, the amplifier still has the original 1977 date coded Eimac 3-500z tubes installed and making full power!
IMO the Drake L-4B has one of the better RF decks built during that era. However, the amplifier does have a few design flaws that IMO should be corrected. Therefore, I decided to modify the amplifier to resolve those issues and to also update the power supply. Due to the age of the L-4B, I installed a new updated power supply board that included all new diodes, resistors, and capacitors. The new board eliminated the two separate capacitor boards and added additional capacitance as well.
The problems with the L-4B are twofold. First, in it's stock form a surge from the high voltage power supply flows through the HV switch on the front panel whenever the amplifier is switched on. After years of use, the HV switch on the L-4B has a tendency to fail, and a replacement switch is not readily available. The second issue is more common. Similar to most vintage tube amplifiers of that era, they have a considerable amount of voltage and current involved with the T/R switching relay. Many modern transceivers are unable to handle the high switching voltage with using a padding device, or will sustain damage that is expensive to repair.
To correct those issues. I first modified the on/off switching circuit by installing a vacuum relay to handle the HV switching. The high voltage is now handled by the vacuum relay and the front panel switch now only handles 12 volts and 30 mils of current. The second modification I installed is a small optical keying buffer. That circuit now handles the internal higher voltage T/R switching and thus the transceiver only has to sink to ground, a low power/current signal to place the amplifier into transmit.
I am always on the look out for equipment that will place the most weak signal SSB contacts into my log. I recently acquired a Yaesu FTDX-9000mp that includes the 400 watt PA and decided to put it to a real world test against an IC-7700. My testing indicated that there was no significant difference in performance between the two for weak signal SSB reception. Therefore, I decided to sell the IC-7700 with the intention to purchase another rig at a later date that was more recent in design. The next rig I purchased was a Yaesu FTDX-3000, and discovered that it's performance was very close to that of the FTDX-9000. However, operationally the FTDX-9000 was a better rig for my style of ham radio because it is less menu driven. Therefore, I sold the FTDX-3000. The most recent purchase is a Kenwood TS-990S. I've only owned the TS-990S for a relatively short period of time, but in relation to weak signal SSB DX contacts I have made, the TS-990S has proven to have better performance than the FTDX-9000. I have written E-Ham reviews of both transceivers and they can be read here.