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David Robbins, K1TTT



2018 Maintenance and Upgrade Blog

Schematics Index

1/12 First big thing of the new year... bought a 2nd FT-2000 to put on the right radio of the SO2R station. It arrived today, got firmware updates, and was cloned from the left one. Seems to be working ok.

1/14 OK, first contest done with two FT-2000's on the SO2R station, now to finish the job. I modified both of them to change the function of the RX ANT OUT jack on the back of the radio. This is a more permanent modification than the Y cable I made for the FT-1000MP's and involves a little bit of soldering.

This is the location of the Sub RX board on the right side nice and easy to get to, the RF In jack is the one at the far top left corner of the board. The RX ANT OUT jack is the BNC jack on the right side of the Antenna board on the back bulkhead.


The modification removes the jumper from the Antenna board to the BNC center pin and adds a coax jumper from the back of the RF In jack on the Sub RX board to the RX ANT OUT jack. This splits the RF going to the Sub RX after the antenna switching, attenuator, preamps, VRF, and microtune(if you have it), but before the first mixers and roofing filters.

This is the connection to the Sub RX board.


And the connection to the RX ANT OUT jack.


And what the SO2R station looks like with two FT-2000's.


Added notes that were sent in email to YCCC reflector:

Now that everyone wants their SDR panadapter after Tom’s presentation, here are a few notes about easy ways to do it on the FT-1000mp/mk-v/field and FT-2000 series radios… which will likely work for other Yaesu radios that have similar arrangements for splitting the antenna inputs to feed the sub receiver board.

On those radios the sub receiver is fed from a power divider that splits the RX signal after the attenuators, preamp, and wide bandpass filters in the front end. This makes a perfect place to split the signal again to feed an SDR so it takes advantage of the front end antenna switching (including the RX antenna selection) and provides automatic protection from overload, even in SO2R or multi-tx environments.

This can be done for experimentation with no permanent modification to the radio by creating a Y cable to split the signal at the input jack on the sub RX board. On the FT-1000mp that is at the top back corner of the sub RX board which is the vertical board on the right side of the radio. To do this you only need to take off the top cover, plug in the Y cable and route the cable out the top hatch. I made a cable from salvaged parts from a lightning struck radio I was given, but I am pretty sure these are the connectors if you want to start from scratch: https://rfconnection.com/taiko-denki-connectors/

A more permanent mod repurposes the relatively useless RX Ant Out jack by soldering a small coax to the back of the Sub RX board input jack and running that to the RX Ant Out jack on the back panel. I have done this on two FT-2000s now. On the FT-2000 the input is on the top front of the Sub RX board which is still mounted vertically on the right side of the radio. To do this you take off the top and bottom covers, unscrew the board so you can get to the back of it, solder on the cable, unsolder the connection to the RX Ant Out jack and solder the new cable to the jack. On the FT-1000 series that is harder to do because where the RX Ant Out jack is located, you could just repurpose the Ant-B input if you aren’t using that or just run the cable out the top hatch to the SDR.

1/15 Did a quick tour of the Beverages today, despite the ice and wind recently they are all just fine.

1/29 Nice morning for January, 28f, light breeze. Fired up the chainsaw and continued cutting smaller trees (3" or less), and one big one (a 2 trunk maple about 10" at base), in the 40m RX Array area.

2/10 K1MK complained about the SWR being high on the 80m 4-Square. Found the East vertical's feed point broken, fixed same. With temperatures over 40f and light breezes who could resist some antenna work! Went up 30' and realigned the bottom 10m TIC Ring Rotor that must have slipped in one of the ice storms.

2/19 Been playing with different SDR's for use with N1MM+ new spectrum display window. Started with the SDR-IQ that I have had for years as the baseline, while it is good it is discontinued. I tried an RTL-SDR based one in direct sampling mode, but it had horrible image problems and lacked sensitivity even though they had added preamps to it. An SDRPlay RSP-2 performs well but requires using N2IC's Waterfall Bandmap program as an interface to N1MM+. Now N1MM+ has added a direct interface to the AirSpy HF+ which is also quite good, though a bit more expensive than I hoped for. Will test that for a while now before modifying more radios.

2/20 Warm day for February, was over 60f for a while. Did some more cleanup in the 40m RX Array area, lots of branches down from cutting in the fall and winter winds.

2/21 Another warm and sunny morning. Did some more cleanup in the 40m RX Array area.

2/24 Ice then wind last night, took a stroll around the Beverages. Only found some small branches down on the N/S one, but found a couple trees that a Pileated Woodpecker had been pecking away at. Both had dead cores, one that was just a honeycomb of passages done by carpenter ants, they'll both have to come down this year.

3/11 Nice skiing day for March so took dogs around Beverage trail. Found one tree broken off on the NW/SE Beverage. Made rope sling for chainsaw and went back to cut it off to get the extra strain off the supports. No insulators came off until it sprung back up, then one popped off.

Tree down:


Cleaned up:


3/16 Had to carry ladder through knee deep snow to each of the 160m Inverted-L feedpoints to find that the second one (of course) had come disconnected.

3/19 Over the weekend the 120' 10m rotor decided to freeze at 30 degrees or so... today I was able to get it moving. It appears the pot is intermittent causing the control box to protect it by shutting off rotation one direction or the other. With a jumper I can at least fool it into turning and get it pointed in a more useful direction for now.

3/31 NT2X was here and helped push buttons to test after I went up and realigned the 60' 20m rotor. I also put the 120' 10m rotor back in service as it seems to be working ok now that the temperature is above freezing most of the time. There must be some water in there that freezes up the indicator pot.

4/11 Cut down the last of the dead or dying scotch pines between my old shed and the first set of 40m RX array verticals. Only about 20 more in that area, most of the bad ones are down between the 40m RX array and the 40m 4-Square array, that's probably where I'll start cutting next.

4/14 Cut some more dead and dying scotch pines in the area between the 40m RX array and the 40m 4-Square array. All of them had to be pulled away from the 4-Square as they all only had branches on the one side making them unbalanced.

4/21 Still some snow on the ground and too wet near the 40m 4-Square so I cut some more pines in the middle of the 40m RX array on the road side.

4/22 Cut 3 more of the larger pines in the 40m RX Array area, I think these were the last in the upper half of the area. The lower half will be more work as I'll have to lower the feedlines that follow the trail down to the pond for several of them. Because the ground is still pretty wet all of the ones cut in the last two days need their stumps cut level with the ground.

4/23 I untied the 40m array's feedlines and put them on the ground. I then protected them in a few places with previously cut logs. Then gas up the chainsaw and cut until both the me and the saw ran out of gas. I got all the pine trees along the path down that really needed to go and then started limbing and cutting up the trunks into moveable pieces... not quite done but I'll be able to finish it tomorrow then start a big cleanup.

5/8 Now that the snow has been gone for a week or so I have gotten the last of the branches and trunks of the trees along the 40m array's feedlines cleaned up. All that is left now are the tall stumps that need to be taken down to ground level.

5/10 Installed RPON module on the right ACOM 2000A and set it up for remote control. The RPON worked out of the box with the USB-COM cable so it appears they have fixed the problem I had with the first one. The ACOM Director software had to be modified though as it did not want to run two instances on the one computer. Fortunately M0YOM has made the source available and I had the correct version of Visual Studio to modify it. The remote station can now control the right radio and amp for remote SO2R operation.

5/15 Finally got the last of the scotch pines down in the 40m RX Array area.

6/2 NE Beverage was reported to be dead. Resistances at the near end to the transformers were ok, but were open through the reflection transformer. It was cool enough, but very humid, so I dressed up with long pants, boots, long sleeve shirt, DEET, a 1911, 2m HT, and a bucket with a spare transformer and some tools and went back to the far end. About half way back there was a large maple tree down on the wires so I had to replace lots of insulators and later make a 2nd trip with the chain saw to cut it up. At the far end the reflection transformer resistances were ok, but I replaced it anyway. Testing on 80m with some daytime ragchewers sounded ok.

6/11 In between cutting grass and tending to the garden, today I mostly finished off the mechanical updates to the 40m 4-Square feedline where I had taken down some of the trees it was tied to. I had to plant 2 pressure treated 2x4's that had been tied to the tree stumps that I had left 4-5' tall. Then I cut down the stumps and moved them to the rifle range fence/rock protection. Then I went through with a ladder, tape, and short ropes to readjust supports so the cables were higher off the ground in a few places.

7/2 Here are a few notes that I have written in response to either FaceBook postings or direct e-mail questions... just because someone out there may like to reference them in the future.

  • Stubs a source of noise????
    • In answering an email about stubs used as filters (see Filters and Stubs, in particular the K2TR design). On open ended stubs the typical method just cuts the end off to tune them and maybe then just wraps the open end in tape or shrink tube. Bad idea... cut the center conductor short and tape it then wrap the shield over the cut end and solder it up. The unterminated end of the shield can allow noise on the shield of the stub (which is likely connected to the dirty shack ground one way or another) to couple into the coax resulting in rx noise. And maybe the other way, injecting some TX RF into the ground, though that is harder to measure it in a consequence of the reciprocity principle.
    • I used an SDRplay RSP2 and just measured one birdie here using a piece of RG59. Touching the shell of the F-connector to ground gave me one stable spur from something about 15db above the noise floor around 10MHZ. Just wrapping the connector in aluminum foil reduced it to 5-10db. These are not great connectors and maybe not well shielded cable so likely some leakage through shield, but at least an S unit of reduction from a wad of foil around the open end. In a high RF environment that could add up to lots of RX noise leaking in. This will not affect the way the stub works.

  • Other notes on stubs and filters to reduce inter-station interference
    • The use of stubs to reduce receiver overload like is done in the K2TR design on the high bands (see K2TR stubs) I think is better done with lumped filters between the radio and amp if possible. You can get better attenuation and the filters can be switched easier if the radio/amp pair is used for multiple bands.
    • Should I add stubs to reduce inter-station interferenc? Stubs shouldn’t hurt, but they may not help depending on the source of the harmonics. First, look at my analysis of single and double stubs at: Tech Reference - Filters and also some of the other notes there about how they work and how to tune them. Since most of that work was done I have used other meters and a vna and think the vna is the best tool for tweaking lengths. Note that 30db of attenuation for a stub is about the max you can get, they won't get rid of harmonics but should help in some cases.
    • One thing that will totally destroy any application of stubs or filters are rectification sources outside, or even inside, the shack. Remember the stubs and filters only work on the signals inside the coax that they are connected to, if there is a source of harmonics or a noise generator outside the coax they won’t do anything to attenuate it. Besides the obvious ones like metal gutters, bad connections on guy wires, and all those outside things, beware of odd effects like the one I found last year with a wall wart: RFI Hunt . This one was picking up my 80m signal, spreading it out on 40m, and modulating it, just something else to keep in mind.

  • If you use RCS-8V's or similar switches in the shack, wrap the plastic cover in foil to prevent noise pickup and radiation from the traces and relay jumpers.

  • Don't count out commercial radio equipment as sources of noise! Not all of it is as well designed as it may look, and may not have been tested in all possible combinations with other stuff, power supplies, external cables, etc.

  • About using SDR's to study RFI: I don't care what the waveform is, how often peaks repeat, or what it sounds like, if it isn't supposed to be there its got to go. In all the crap I have hunted down there are 2 types of noise and you can pretty much separate them by ear and a quick turn of the big knob... It is either a continuous raspy arcing sound or a continuous buzz or hum often with periodic peaks. The raspy one is usually power line related, bad insulators, bad connections between guy wires and grounds, etc... The periodic peaks is something electronic... MAYBE you can get some information on the periodic one by studying the width of the peaks and how stable they are, but its not like each particular device has a specific signature. Its more generic like 'wide unstable peaks' are most likely a non-critical device like a battery charger or motor controller, 'peaks that shift when the lights flicker' are probably directly connected to the power line rather than from computers or video, 'thin stable peaks' are something with a good clock like a TV or monitor or other computer related device.

  • RFI hunting notes:
    • Unless you can see something turning on and off in sync with the noise DON'T ASSUME ANYTHING about what it is.
    • In response to people buying special receivers covering certain bands or modes to find noise: Pick a frequency, any frequency where you can hear the noise and preferably nothing else, my preference is either the highest you can hear or the lowest.
    • FIRST eliminate EVERYTHING in your house, its most embarrassing to raise a big stink trying to find something outside just to find your computer power supply has gone bad or your new LED bulbs make noise! Remember UPS's can make noise when the breaker is open! Listen on a battery powered radio and turn off every breaker in the house one at a time. When they are all open turn off UPS's and any battery powered electronics, tablets, pads, clocks, etc. If you find it that way, the best fix is a sledgehammer and then quietly let the discussion drop. if not, continue on...
    • THEN start hunting with a directional antenna(usually fastest) or signal strength meter(slower). Don't spend big bucks or lots of time in the beginning, if you can hear it on your car radio when it is on AM and not on a station use that to get an idea of how far away it can be heard. A battery powered short wave receiver is excellent(I use a Grundig G5), especially if it has a ferrite or small loop antenna, but a built in whip works also. If you get close enough and can hear on an AM Airband radio (many older 2m ht's cover that band) use that. Remember, it takes lots of energy to make a really wide signal so if its loud and covers lots of bands it is likely very close or very big! Don't know how directional a handheld radio is? Just tune in a known station, hold it and turn in a circle while watching it's s-meter... usually nulls are easier to distinguish and better to hunt with as the AGC in most radios will flatten out peaks.
    • DON'T LET IT GO ON VERY LONG, THE LONGER IT LASTS THE LESS LIKELY IT IS TO BE FIXED! If you don't know how to hunt or don't have any portable radios get help, there is always someone not far away who believes they are an expert and can help. The longer it lasts the more likely it is that if you find it in a business or someone else's house they will say "it can't be here, i don't have anything new"... Catching it early may help convince the culprit that they have something really bad and should return it or get it fixed. Use the example of a bad doorbell transformer suddenly causing noise because it was going bad and could start a fire.

7/27 Hmmm, not keeping up to date here. Last weekend I had to replace one of the Beverage boxes because a nearby lightning stroke damaged it. It was quickly fixed and put back in spares as it was only a burnt wire, all the transformers were ok. Just checked the other two boxes and they look ok still. I've been doing more stuff on the house, garden, yard, etc since spring. When wx is bad I've been working on the scripts for the SO2R/Remote station operation and have made it a bit easier to setup and maintain.

Some of the house work has been helping George turn some boards cut from a birch tree we took down 2 years ago into tops and seats for the picnic table and the two small deck tables... here they are during finishing with stain and spar urethane.



7/30 Repaired fixed south 6m Yagi. Part of the reflector had broken off from vibration. Unfortunately it used a tubing size that I didn't have much of in stock, and nothing long enough, so I just made a splice from the next larger size tubing.

8/4 This is a response to an email with some questions on measuring and tuning filter stubs.

Question: I cut some stubs this morning using an AA230Zoom antenna analyzer. I used the R,X display, and just adjusted the stub length until the R and X lines crossed (resonant frequency).

Answer: Where they cross is not resonance, resonance is defined as x=0, normally for a stub the r will be either small or large depending on if you are measuring open or shorted and which multiple of ¼ wave length the stub is. This is some random piece of cable that is an odd 1/4 multiple of a wavelength open ended stub at 23mhz or so, in this display you can see the small R at about 23mhz, and see X going from negative to positive right around that area, but on the rigexpert its too hard to read at this scale so the next image is zoomed in…


Notice now you can see X crossing zero to the left of X=R at whatever small value of R that is. Also note that to get good readings on the rig expert (or vna for that matter) you need to scan as small a range as you can to eliminate large frequency steps between plot points.


Question: I then took the stub and put it on the VNA. Since there is only one port on the stub, I hooked it up to the DUT port of the VNA. That limits what I can see on the display; I seem to get representative displays of data when using the |Z| variable, and the THETA variable (not sure what that is). Do you have another variable that might be more indicative of performance?

Answer: Using a single port on the vna is fine, this is what mine looks like on the same stub as above.


And zoomed in with a frequency marker added to read R and X as close as I could get to X=0. You can see from this that resonance is at 22.94MHz but R=X at 23.07MHz.


Question: The VNA is telling me that the stub is really cut too low, i.e. on 40M, the both variables bottom out about 6800, and start to rise about 7150. I would expect that, as the stub "resonant frequency", according to the antenna analyzer, was 7020. I guess what I'm looking for is a validation of what I'm seeing, and that I should raise the stub resonant frequency so that the "bottoms out" covers the 40m band.

Answer: What I have found is you probably want to tune for X=0 in the pass band… for this stub I am playing with that would look like this at the 15mhz resonance.. note that with a large R the X changes much more quickly also so I would really have to zoom in more to measure it accurately… but if the band I was looking to pass was around 15.2mhz this is what I would want to see, a very high impedance and x=0.


Now… level 2… to get a view of the real world hookup the VNA like this… the stub is the fat cable hooked to the T in between the DUT and DET ports…


This lets you measure the transmission loss in the passband and the rejection in the stop band… the passband looks like this with a frequency marker at the resonant point:


Then a stop band looks like this showing that at phase=0 the transmission lost is almost 26db, about what you would expect for a coax stub. Tuning using the max loss is normally going to be more sensitive than min loss, I usually flip back and forth to get the null where it does the most good, but also making sure I don’t mess up the impedance in the passband by very much.


Oh, and another advantage of measuring like this is that the real world connection of the stub will likely by to a T connector like this so the length of the connectors is already taken into account. You can also test multiple stubs complete with all their connectors and any cable in between them.

As far as differences in exact frequency measurements, mine are obviously off a bit also, some of that is calibration, its been a while since I have checked both of mine… some of it is frequency step size and how close I tried to get to the zeros.

Another measurement technique that can be useful is to hook up the zoom like this. The black taped up thing is a low power 50 ohm non-inductive load.


Using that the best option on the RigExpert is probably the All Params reading, using that you can step frequency up and down to get X close to zero and see what the impedance and return loss (RL) are… remember RL is the inverse of TL that the vna gives you so a small RL is what you want in the stop band and a large RL is good in the passband. There is a way to convert RL to TL and vice versa, but if I remember it’s a bit ugly.

Doing this the pass band looks like:


And the stop band looks like this:


8/5 Hmmmm, one radial on the 80m 4-Square was down this morning. It wasn't broke, it wasn't pulled sideways like a moose would do, it was just pulled like something heavy landed on it and pulled the aluminum out of the knot at the end post. Put it back up and broke off some green maple that was growing over it.

8/17 Replaced pot in 15m 30' TIC Ring Rotor that failed open last week. Autopsy on the failed one didn't show anything more than just some corrosion gunk in it, the wipers were all intact.

8/24 The summer humidity is taking a break and the wind wasn't too bad this morning so I finally went up the 10m tower and replaced the Yaesu G-1000SDX at the top with a G-2800SDX... It was close, I needed a shoehorn to get it under the clamps, but it fit. The picture shows how much room was left.


8/25 Well, the G-1000SDX I took down yesterday only appears to have a broken wire. I soldered it back on and will need to test the pot some more when K1MK is done doing his contest as my ohm meter doesn't like rf. This is the broken wire.


KB1W let me have his broken rotor after we replaced it back in the spring. I opened it up to see where that wire should go and to see if his pot was ok in case I needed a replacement. There sure wasn't much left in one piece inside it:


9/2 Found the SO2R left radio bandpasser 40m filter section was bad. I replaced both the 33pf and 27pf caps, though only the 33pf was blown... this is the second time that one has blown, probably time to figure out an upgrade for the next time!

9/18 Whew! Busy morning in the rain... In the middle of wiring in a new outlet for the microwave outside the shack so I could get rid of 2 extension cords, the septic pumper showed up... yes, in the middle of the 2.5" of tropical depression Florence we have had so far before lunch! Then after lunch, just for fun, I added a pair of flood lights above the lightning protection box to cover that side of the house.

9/23 Reconfigured 160m feedlines and remote switches. I essentially took an RCS-8V that was on the outside wall of the shack and moved it to the 160m table. This required adding a new feedline through the lightning protection to the 160m table and then connecting a new RCS-8V on the table to replace the one outside. I was doing this partly for cleaning up some of the cabling, but also to try putting MT-3000a tuners on the antennas to see if they could be evened out a bit better to help the amp tuning out. The tuners didn't help. The inverted V is good enough already, and putting one on the inverted L's let me move the minimum SWR all over the band, but made the bandwidth narrower so it would have been harder to tune. So the tuners go back in the store room for some other project.

10/4 Started the Fall brush and weed cutting around the 20m tower.

10/5 Continued brush and weed cutting, this time around the 80m 4-Square. Also toured the Beverages, no damage found on them.

10/6 It was supposed to be sunny and cool today, but instead it is 48f, cloudy, foggy and drizzly... So instead of spending more quality time with the DR Mower I decided to replace the 80m FT1000mp RIT encoder that has gone flakey. If you have a well used FT1000mp you have probably seen this. The control becomes intermittent, jumps around, or only counts up or down no matter which direction you turn it. These are mechanical encoders and just wear out after lots of use, unfortunately they are not the easiest thing to replace... unless you know my special modification to the radio to make it much easier.

First, the controls are Bourns part number PEC16-4015F-N0024-ND which as of this writing are available from Digikey, Mouser, and other parts suppliers for about US$1.28. I bought 10 of them a couple years ago and still have 6 left.

The FT1000mp front panel is plastic which covers lots of controls that are mounted in various ways to a metal back support. The metal support is designed to be easily folded down using 2 screws as a pivot point. Yaesu obviously was expecting some need to access this control separate from everything else because it is on it's own little circuit board. The board is held on from the back of the metal panel with 2 screws. Unfortunately they also put the shaft nut on the other side of the front metal panel. To do the replacement without modification requires removing the plastic front panel which is a real pain, you have to remove all the knobs, disassemble the shuttle jog and main tuning tension stuff, and then be sure to get it all back assembled and aligned, I always have trouble getting some of the buttons to align and work properly after doing that... so, I came up with this much quicker and easier modification.

The replacement goes like this:

1. Remove top and bottom case covers.

2. Pull knob off RIT encoder and modify the front panel to allow removal of the nut. I simply use a pencil soldering iron to melt the sides of the hole around the encoder to make it big enough to reach the shaft nut with a pair of needle nose pliers. Fortunately the RIT knob is big enough that it covers the enlarged hole. It looks like this when you get it big enough...


Once the nut is loose you can usually unscrew it with a pocket tweaker size screw driver. It can help to cut off the shaft of the encoder as I have done to make it easier to access the panel with the soldering iron.

3. Fold down front panel. To do this you remove the two flathead sheetmetal screws on the top center of the panel. DO NOT remove any of the screws holding plastic to metal, only the two holding the metal to metal joint. Then on the right and left side loosen the bottom screw in the crescent shaped slot about 1 turn. Then remove the top screws on both sides. At this point the front panel is loose from the chassis, I normally slide the whole radio forward so the front panel can fold down over the front of the table like this.


4. Take two screws out of encoder board. This is the encoder board under all those other wires.


There is enough slack in the wires to allow it to be pulled out from under the other wires and propped up on the side of the front panel like this.


5. Unsolder and replace encoder on the board. I use Soder-Wick to suck the old solder out of the 3 connection pins and the 2 side clips then pop off the old one and solder on the new one.


6. Reverse process to reassemble. I have replaced the nut on the shaft on some encoders, but don't think it is really necessary any more as there is no way for the encoder to back out of the hole and there is no real turning torque on the control.

Total time is about 1/2 hour as opposed to the 2 hours or so it takes me to disassemble the whole plastic panel and put it back. A similar process is possible to touch up the solder joints on the small headphone jack that become intermittent because they DIDN'T put a nut on that one!

10/14 Still no frost or freeze, but did more brush mowing anyway. Finished up mowing pretty well around the 80m 4-Square.

10/21 Finally had a good frost and over night freeze. Finished up the brush mowing around the 15m tower for this year I think. May hit a few of the bigger patches of choke cherries if there is time but the weeds are starting to lay over already. Time to store away the summer yard equipment, take off the mower deck, and hook up the snow blower.

10/28 Big winds broke off a whole tree across the NNW Beverage, will need chainsaw later to clean it up.

10/29 W1TO donated another FT-2000 to the station. I installed it on the 20m station and modified it for use with an SDR.

11/3 Sold 2 of the old FT1000mp's so went and bought 5 new Airspy HF+'s to outfit the rest of the stations with the N1MM+ Spectrum display capability. In doing that I decided the way I had modified one of them was ugly, but had been good for testing the capability. So I removed that mod which was described earlier and in it's place I repurposed the antenna B input to be the RX Antenna output for the SDR. What it amounts to is cutting the cable that goes to the sub receiver and soldering it to the antenna B jack that is right under it. This disables the antenna B input but allows easier connection to the SDR with no wire running out the top hatch on the radio. A completed mod looks like this:


This is the cable modification described last year. It works by plugging in to where the cable above connects to the sub receiver board and tapping off the signal to a cable that ran out through the top hatch on the radio.


Modified all 5 of the remaining mp's.

11/4 Checked all 4 Beverage paths today. Nothing new down on any of them despite recent high winds. I did take the chainsaw out the NNW path to cut up the tree that came down on that one a week or so back. Later I took the chainsaw out the NW/SE path and took down a bunch of dead pines near the start and pushed back some stuff that was encroaching on the trail.

11/5 Stack of Airspy HF+ SDRs showed up today. Had to upgrade firmware on all of them and then just plug in to the 5 single band stations. I installed the software as I was doing the modifications to the radios over the weekend so everything is ready to run now.


11/9 Waiting for rain/snow to start so went out and cut off a bunch of the scotch pine stumps that I had left from the spring cleaning in the 40m RX Array area.

11/10 Found the top of a dead pine tree down on one of the 160m Inverted-L radials, fortunately it was dead enough that it broke apart and was easy to pull out of the way.

11/11 Found a really large branch had come down on one of the radials for the 40m 4-Square array. I untied the radial and put it back over the branches, will need a chainsaw to clear it out of the mow-able area around the verticals.

11/12 Ground is starting to freeze so I took a while and cleaned up lots of downed branches and those stumps I cut off out of the 40m RX array area.

11/23 Top 40m rotor power supply is blowing fuses. Motor resistance seems ok but current is high.

11/25 Was trying to use lower voltage battery supply to exercise top 40m rotor, it seemed to be working as the current was coming down but then it stopped turning and the resistance went way up. Guessing that an outside connector burned from the high current, hopefully not the motor itself.

11/26 Received another FT-2000d, this one used from HRO. Modified it for SDR output.

11/27 Replaced RIT encoder on the 15m FT-1000mp.

11/28 Put latest FT-2000d on 80m station.

12/1 Nice day... bad news... it finally got above freezing and the wind quit so I could go up and test the top 40m rotor motor. Its bad. I am guessing either one or more commutator segments are burnt or some rotor windings are burnt. It has a ground fault of about 25 ohms and intermittent high resistance across the power leads. It will actually spin once I get it started with only 36v on it, but it won't always start on its own.

After getting off the tower I took the dogs skiing down to get the mail. All the trails along the field and around the pond have stuff blocking them. Also several radials on the 40m 4-Square were down because of broken branches, trees, or an insulator. Got all of those radials up so they don't get frozen down in the ice storm expected tonight. Also checked the 80m 4-Square, all its radials are up but some may be touching branches, those will have to be checked before the next multi-band contest.

12/5 The 40m 4-Square radials on the pond side are under broken trees/bushes, whatever those ugly weak things are. Will take a visit from the chainsaw to clean them up.

12/6 The early morning dog walk turned into a repair session. First the NNW Beverage trail is blocked in several places by bent or broken trees, the wire is still mostly up I think so maybe I'll clear the trail later. Then when we got out to the 150' tower I saw this new broken off pine tree hanging on the ropes for the WARC inverted Vs. I had to untie all 3 of them to get it untangled as it was just a bit too far off the ground to lift it off. Got them all tied back up just as a light snow started. Walking on the old snow is kind of a pain right now, its only 6-8" deep and crusty, but not strong enough to walk on all the time, so you take a couple steps on top, then break through a couple, then on top, then break through, etc, etc, etc, very tiring. And all that done before 9am and my morning quota of caffeine.

Well, after the first snow shower was gone and I had my caffeine fix I took the chainsaw down to the 40m 4-Square and cut down most of the broken stuff. Then I got the radials all back up and clear of branches for a while. I also cleaned up some other broken off stuff on the other side of the stream and near the road. Most of the stuff I cut will have to wait for a thaw to be removed as its frozen down in the snow now.

12/13 XX Towers was here to take down the 180' K0XG rotor drive unit. It was a beautiful day in the Berkshires. Almost 20f, light breeze, and of course SNOW! Here is Andrew getting ready to climb.


There was a plan to replace the motor and put the drive unit back up... I was giving it about a 50-50 chance of happening. We lost. We couldn't separate the bad motor from the top gearbox (the top blue box below). After a couple hours of prying, penetrating oil, hammering, heating, etc, this is the last attempt using the 3/8" rods and hold down bar that held the motor in place to try to pull the shaft out.


I took the nameplate data and found a NOS unit for about $200, ordered that and had a stiff drink.

12/14 I was able to pull the chain drive sprocket off the output shaft, so replacing the gear box is possible. The output shaft was well rusted


I tried a couple more times to pull the motor shaft out, this is where I left it. No, the bent rods and bar are not a camera lens defect, I bent them and still the shaft won't budge.


I did get the pulse sensor and magnet on the new motor at least.


12/15 Tried one more time to unstick the motor shaft, this time by taking off the outer case so I could hammer on clamp on the end of the shaft. It still isn't budging. I took the motor and top gearbox off the support bracket to make it easier to handle and changed the oil in the lower gear box. That oil was nice and clean, though a bit thick, even after warming it up a bit. I flushed it with some synthetic 5w30 then refilled with the same stuff and closed it up. I tried to remove a side cover on the top box, the only thing that appears to provide inside access, but couldn't break it loose, I bet it was press fit on a gear bearing. I did open up the oil hole and the stuff inside was light brown and milky, so there was probably some water in it from the input shaft from the motor.

12/17 Ice, sleet, snow last night. New gearbox in transit. Started updating station web pages with new pictures that NT2X took the last time he was here.

12/18 Gear box due today. Thought I would document the new (and old) parts for later if needed.

Motor: 3/4 hp 1750 RPM 90V DC 56C Frame TEFC Leeson Electric Motor # 098032 Top Gearbox: Tigear MR94752L1 56/175-15 15:1 right angle reducer (but bought MR84752LK as replacement) Bottom Gearbox: Alling-Lander Model 192-v-01r-134 35:1 right angle reducer

12/19 Finished up assembling the drive unit to go back up the tower hopefully tomorrow. I didn't take pictures of a lot of the work as it was often greasy or dirty. So here are a few:

The whole thing bolted together without covers.


The top PVC cover adjusted to fit over the motor flange.


The retaining straps on the top cover and a safety cover over the back side shaft that isn't being used.


The magnet and reed relay pickup for the position pulse counter.


The upper gear box. One of the messy things was filling the top cavity of the gearbox with grease to keep water out.


The lower gear box.


The output gear.


Tested in the shed at about 15f...

Motor resistance 4.3ohms With 50v running current about 5A.

12/20 Beautiful day for tower climbing, would do it myself if I had a capstan and operator, but got XX Towers here instead so I stayed on the ground to test it once it was connected.

Andrew on his way up against perfectly clear sky.


The ropes, tool bucket, and motor assembly all ready to go up.


Matt doing the hard stuff.


The motor on the way up.


Andrew installed it, spliced in the pulse switch cable, and then watched it while I tested from the ground.

Resistance from shack= 5.6 ohms across motor, infinite to ground. On tower with 50v running current=4A With 90v starting current about 5A then runs at 3.4A Temperature about 35f.

12/23 Walked the Beverages this morning because too much of the snow melted in the rain on Friday. Big winds yesterday and last night brought down a lot more branches and trees but most of them missed the Beverages. There is one across the connector trail that will need a chainsaw to get cleared.

Well, the dogs successfully lobbied for an after lunch walk so I gassed up the chainsaw and took them back to clean up some of the Beverage trails and then some of the dead stuff around the 40m 4-Square and RX Array.