OTHERS
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This is where the tubes arrive at the post. The first on the left side that goes up contain the two main lines for the beverages and long wires. The second and third tube ends in that weatherproof plastic box there with K9AY line and control cable. From this point, there's a third tube going underground up to the K9AY and finally far right, a short tube was left for future use.
The feed point stands at that big post behind the swimming pool. There are two underground 3/4 inch plastic water tubing containing each two cables. One with two RG6 coax cables and the other with one RG6 cable and one Ethernet 8 conductor cable for remote control purpose. This was a nasty job first burying and then, leaving everything clean after digging and filling back. From that same post, there's another underground cable run for around 8m (30ft) to the K9AY antenna back into the bushes
The first thing you must know when purchasing the MFJ-
Another important detail you must know based on my personal experience and others too is that the potentiometers that MFJ puts in their product are really cheap stuff. After a couple of months of using it, the phase pot was already failing. My first reaction was to send to MFJ an email describing my situation and explaining that I could not send them under warranty because I did some mods on it. Nevertheless, that problem has nothing to do with my mods and it would be kind of their part to send me a new pot that I could change myself. This is what they kindly did. After the new pot was installed, an input gain pot began to fail and even the phase pot began to show weaknesses again! I then decided to change them all with quality pots. I ordered from Newark Canada three Honeywell Clarostat RV4 series potentiometers. They fit perfectly on the 1026 chassis. For the gain controls, you need two RV4NAYSD251A and for the phase control, one RV4NAYSD102A . They are even softer than the original MFJ model. Now, I can say that my modified phaser really gets the job done.
MFJ-
View of the new Clarostat potentiomete rs with input swap mod and grounding switches
View of the high-
Front view of the unit with extra switches
Internal view of one of my three splitters. I used the design described by John Bryant and Bill Bowers in this article. I made them from plastic small boxes for their availability and low price. At the beginning, I've left the primary and secondary windings isolated but after my lightning event , I had to connect them to a common ground to respect the grounding scheme. After that mod, I didn't notice any difference on the reception.
Switching panel with RPA-
This is the version number two. The first one has been destroyed during the lightning strike event after just one month of use. The whole circuit was based on this design . It wasn't necessary to use band pass filters as shown. I made two four inputs identical units on the same board to feed the two phaser inputs. That allows me to use various antenna combinations. With quad NAND gates, I added two more "default" relays. The unit is always powered but I can leave the two most used antennas without switching any relays. I found very clever the use of the LM3914 comparator because with only four wires, I can make the dual switcher work perfectly.
I've also added static protection with gas discharge tubes. I had for over thirty years high voltage wire (in red) that I used to prevent high voltage from jumping to the board, at least, this is what I hope! I avoided soldering them to make sure that the contact to ground would last even under higher peaks.
General view of the unit. All external screws are made from stainless steel. During the summer, I don't expect to leave the unit outside. I don't want it to be damaged during thunderstorms. I will work with only two beverages connected to the manual switching panel.
DX ENGINEERING RPA-
First, when I bought this preamp, I thought in using it near my K9AY loop in a weatherproof
box to increase its overall gain. Then, when I elected to work mainly with my beverages,
I decided to keep it near my receiver and I can tell you that it will stay there.
It all situations, the internal preamps of either the R75 or the Perseus don't match
by far with the performance of the DX Engineering RPA-
Inside view of the remote switcher controller with his array (bunch!!) of resistors.
I've added a new splitter to feed both Icom and Perseus receivers. I had a Radio
Shack TV splitter in my junk box. After pulling out the original transformer, I just
replaced it with the HF transformer as described above. Just another ready-
**Please, see the Noise page for an important update related to my RPA-
SPLITTERS AND SWITCHING BOARD
THE LAPTOP COMPUTER I'm using at my receiving station has been changed in July 08
for a Toshiba Satellite L300D with French Windows Vista SP2 now. It runs with an
AMD Turion X2 Dual-
COMPUTER AND RELATED