19" Radials on the Diamond X50

After reading Runt Radials I ordered some 19" radials from Comet, these also fit the Diamond antennas.

My Diamond X50 came with the 7" radials, and I've had problems with the coax getting "hot" [common mode currents] with RF when using it on 2m.

Here's what the 19" radials look like



Diamond X50 mounted on 2nd level deck. I'm located in the south Puget Sound at 400ft ASL, and have a clear view north towards Seattle (35 miles north), this is a secondary antenna connected to my Kenwood TH-D72 hand held. With 500 mW I can open the 145.190MHz N7GDE repeater located 100 miles north of my location.

While I have not done any form of testing that's scientific, the anecdotal results are slightly better performance on both 2m and 70cm, with the added bonus of the feedline being better decoupled from the antenna on 2m.

I also added full sized 1/4 wave 6m radials to my Comet GP-15, and improved the SWR response.

CHIRP, Kenwood TH-D72 and WWARA DB Extract

How to use the WWARA coordinated repeater DB extract, Excel or LibreOffice Calc, and CHIRP to program a Kenwood TH-D72 - or any other CHRIP supported rig. Noting this to remind my self how to do it in 17 easy steps!

• CHIRP - Free programming software
• WWARA > CSV Database Extract [includes CHIRP formatted file] 
• LibreOffice - Calc / Spreadsheet - used to edit the CSV file [CHIRP sucks at this]

The Process:

1. Create backup of the rig to be programmed, in my case I use Kenwood's MCP-4A application.
2. Download and unzip the Database Extract from WWARA.
3. Open the CHIRP formatted file in CHRIP, and export it as a CSV file.
4. Open the CHIRP formatted CSV file in Calc or Excel.
5. Delete the rows you don't want. In my case I remove the 6m, 220MHz, everything above 70cm, and anything that is not an analogue FM repeater - for that I use the custom column sorting to group repeaters marked as digital together for deletion, and column sort Location numbers again when done to get whats left back in order.
6. Optional, the Location column numbering can be fixed using the fill down function to sequentially number the memories we are keeping.
7. I add in my custom APRS, IRLP nodes, and other things starting around memory location 980. The Location column can skip unused memory locations out, e.g. mine jumps from 266 to 980.
8. Save it as a CSV file again and close Calc / Excel.
9. Open CHIRP.
10. Connect the radio to be programmed.
11. Perform a read/download, and save it as backup.
12. Open the edited CSV file.
13. Eyeball it to make sure nothing is out of place, if so, close CHIRP and fix the CSV file.
14. Clear/delete everything from the tab containing the information from the read/download, copy and paste from the CSV file tab. The exact steps to do this have changed at least once between CHIRP versions.
15. Write the config back to the radio.
16. Done!
17. Not so fast, I then read the config in the Kenwood MCP-4A application again, and save it as a backup.

Comet GP-15 and 6 Meters

The Comet GP-15 is a single piece tri-band antenna that covers 6m, 2m and 70cm. Here's how I improved the 6m performance and SWR bandwidth with full sized radials.

The 6m band is "tuned in" via loaded [1/4 wave on 6m] radial that is adjustable with about 1MHz of bandwidth, the other two supplied radials are 1/4 wave on 2m, and double as 3/4 wave radials on 70cm, which is fine for these two bands. The GP-15 is a single 5/8 on 6m, but the single radial lets it down..

Issues with this configuration, the single 6m radial results in narrow bandwidth, and more importantly, may not properly decouple the antenna from the feed-line! Take a look at:

• Runt radials - This talks about the Diamond X50 and Comet GP-3 with 7" radials [1/4 wave on 70cm] which do nothing on 2m [1/3 of the frequency]. Same theory, since the two 19" radials [1/4 wave on 2m] on the GP-15 do nothing on 6m [1/3 of the frequency].
• Modifications to the Diamond V2000 and similar antennas - This reveals the Diamond V2000 is less than ideal on 6m. Diamond call it a 1/2 wave, which is technically correct, but its more like 1/4 wave with one radial, that performs less than ideally.
• EA4EOZ also did a V2000 teardown, interesting to see what's inside these things.
• Experimenting With 6 Meter Ground Plane Antennas - If these guys have a problem with the single radial on 6m, then it's worth paying some attention to.

Since learning about the compromise radials on these antennas, I decided to try out a set of three full sized 1/4 wave radials for 6m, the comparison:

First with the supplied tuning radial centered around the FM repeater inputs used in Western Washington:

SWR plot on an Icom IC-7300, 50.0 - 54.0 MHz [500KHz steps]. With the supplied tuning radial, the bandwidth is 2MHz at most.

Quite narrow banded! SWR starts to get high at the bottom end of the band with the North American SSB call freq at 50.125. SWR starts to get high again at the upper end of the FM repeater inputs.

Next up, three full sized 1/4 wave radials, I trimmed these until the SWR just started to sneak up from 1:1 at 50.0 MHz:

SWR plot on an Icom IC-7300, 50.0 - 54.0 MHz [500KHz steps]. With three full sized 1/4 wave radials, bandwidth is 3MHz or more.

Very nice, the bandwidth is nearly doubled. The antenna is now usable down to 50.0, and up into the FM repeater inputs in my area.

The 6m 1/4 wave radials I made out of some wire, with lugs crimped, soldered, applied Lanocote, some heat shrink to seal it in, and offer strain relief where the wire is crimped. I attached them between the locking nuts and antenna base where the radials screw in, applied more Lanocote for good measure. The antenna is on a short TV J-Mount on an roof apex, two of the wire radials are laid on the roof which slopes away - note my roof is composite shingle over plywood and not tin/metal as is more common in other countries - the other has a short section of thin nylon rope to hold it up at about the same angle.

I replaced the 6m "tuning" radial with a regular radial like the other two supplied radials - I ordered this directly from Comet, along with three more 19" radials for my Diamond X50 (which came with the 4" radials), total cost with postage $36. Yes they use the same thread and locking nut sizes!

The EA4OEZ V2000 mod replaces the factory radials with an M6 bolt and aluminum tubing which makes the radials self supporting.

Getting Started with Digital Modes (WSPR)

Weak Signal Propagation Reporter

Discovering digital modes for the first time, I found WSPR is a great mode to start with as you can simply start listening for and decoding beacons right away, and have your mind blown at how far away these weak signals can be received when you cant hear anything audibly out of the speaker!

This doesn't cover how to configure the software and radio. There are plenty of guides and docs around on how to get WSJT-X communicating with your rig.

My hope is to capture enough data from the WSPRnet.org database to start building a picture of how well my station transmits and receives signals on HF compared to others by looking at distance per watt stats etc.

I have spotted ZS3D several times over the last few days on 40m at a distance of 16, 233km / 10, 087 miles, and today ZS1OA on 30m, slightly further at 16, 511 km / 10, 259 miles! These stations are probably about as close as I'll get to hearing something from my antipode.

A surprise when I spotted beacons from stations on 630m (472kHz) in Northern California and BC!

After a few email exchanges with Joe NU6O, I learned that 630m propagates best with vertical polarization. Joe is using a 43ft vertical near salt water, 100W transmit power to radiate 1W EiRP [Antenna is 1% efficient], his beacons are regularly decoded in Japan across the Pacific.

I'm only spotting stations nearby on 630m because I'm using a Carolina Windom 80, less than ideal for this band being a horizontal wire with out any matching / loading for 630m, its kinda surprising I heard anything at all.

WSPR can also be used to indicate the possibility of using other modes based on the reported SNR, see https://www.qsl.net/kp4md/wsprmodes.htm

Update Jan 03 2019:

Transmitting beacons yesterday..




Heard by DP0GVN in Antarctica on 30m [10Mhz]!

Heard by ZL3003SWL in New Zealand on 15m [21MHz]!

Since posting this I've had some fun with WSPR including 630m, several more posts here.

I've since tried and liked JS8Call, similar to FT8 but enables keyboard to keyboard QSOs, message relaying, APRS and more.

GM 4T65E Hard Shift Fix

Summary

The GM 4T65-E transmission was produced between 1997 and 2011 and was used in many GM FWD vehicles with the Buick 3800 Series II V6 which is arguably one of the best engines ever made, but that is another story ..

One of the most common problems is the P1811 code or 'hard shifting' after the transmission and engine reach normal operating temperature. Usually after coming to a stop and moving off again. My 2002 Chevy Impala happened to have this problem, which surfaced after I had the dirty transmission fluid flushed - is seems the dirty fluid hid this issue.

• The problem is often caused because the bores in the accumulators become too smooth and the rubber seals in the pistons will grab or bind up when the transmission fluid is hot.
• This causes a long shift which is detected by the computer, to compensate the line pressure is increased. Mostly as a fail safe to prevent slipping clutches from burning up for example.
• The result is very hard gear shifts, especially 3rd to 4th when the torque converter is locked up.
• There are other causes of the hard shifting from things like a faulty MAF sensor, to faulty shift solenoids among other things, servicing the accumulators is not much more work than doing a fluid/filter change (which is probably overdue anyways) then you can at least rule this out.

There are two options, one cheaper than the other:

1. Cheap and nasty option is drop the pan, remove the accumulators, scuff the bores, change the filter & put it all back together. Refill with BrandX Dex III ATF and call it a day.
2. The more expensive route is to also install a shift kit while we're in there & replace gaskets and seals in the accumulator, refill the transmission with Dexron VI or Allison Transmission TES 295 ATF fluid.

Parts & Fluids

Following the more expensive route this is what you'll need:

• 4T65E Shift Kit Combo Kit from Triple Edge Performance. Everything you need, this is what I got.
• ZZPerformance also sell a 4T65E Shift Kit.
• Allison Transmission TES 295 approved fluid. If you cant find the real stuff locally stocked anywhere, Amazon currently (09-Jul-13) sell Mobil Delvac in a 1 gallon pack and a 4 pack containing 4 gallons. Qualified for free shipping when I ordered the 4 pack.
• Brakleen - used to clean the parts removed - it leaves no residue and should mention this on the can.
• I found one can was only just enough for cleaning the pan, accumulators and those aluminum pipes. I would suggest two cans. This stuff is pretty toxic, spray the parts down outside away from everything into another plastic pan.
• List of tools to be added.
• Some gloves probably a good idea too.

The TransGo shift kit also includes parts that can only be replaced during transmission rebuild. The first side of the info sheet as shown above is only relevant when doing this fix on the accumulators.

Why TES 295

I spent a number of hours researching automatic transmission fluids and this is what I found:

• All Dexron-III licenses expired permanently at the end of 2006, and GM now supports only Dexron-VI fluids for use in their automatic transmissions, it is backward compatible with Dexron-III.
• Fluids asserted by their manufacturers to meet Dexron-III standards continue to be sold under abbreviated names such as Dex/Merc, but the licensing system no longer exists. These fluids are not regulated by GM.
• Allison Transmission TES 295 is a good replacement for transmissions specifying Dexron-III. It exceeds the specification, doesn't lose viscosity with age or oxidize as easily as Dexron-III. It is also rated to -54 °C, desirable here in Fairbanks Alaska where winter temps range from -20 °C to -50 °C.
• If you don't want to spend a bit extra then go for Dexron-VI.
• TES 295 and Dextron-VI work out cheaper due to extended drain intervals.
• Former Allison Transmission Fluids Engineer answers question about TES 295. This is where I got most of the info about TES 295 from, there are about 60 pages of posts so I mostly skimmed over them reading the replies from Tom (hzjcm8).

The Procedure

Most of the information is borrowed from these forum posts, so the credit goes to these guys for writing up what they did:

http://www.gmforum.com/4t65e-hd-147/installing-shift-kit-4t65-hd-transmission-279684/
http://ls1tech.com/forums/ls4-performance/1311880-trans-go-shift-kit-installed-first-impressions.html
http://ls1tech.com/forums/ls4-performance/628840-shift-kit-install-very-detailed-56k-go-watch-movie.html
http://www.w-body.com/showthread.php/32132-4T65E-Do-It-Yourself-Shift-Kit-Instructions-and-Install-Guide

• Ideally you'll want to do this when the transmission fluid is hot. In my case it was a 20 mile drive to my wife's parents place where her dad helped me do this - so the fluid was good and hot. I left the car idling while we got everything ready.
• The ramps we had were too high for the low plastic bumper, so we jacked the car up with a trolly jack, and placed 2 axle stands under the sub frame, and two where a jack normally goes when changing a tire.
• I placed a big piece of cardboard under car, and the large plastic tray that can hold at least 4 to 6 gallons so it's not too full when it's time to move it.
• DISCONNECT THE BATTERY NEGATIVE LEAD!
• Images are from different places, they are not all from the same car, so things look different in some of them, but the transmission it self is the same.

Dropping The Pan

• The pan bolts are 10mm. Carefully loosen each pan bolt, then at one corner loosen them more - I did this on the front middle corner.
• You may need a flat screwdriver to carefully pry the pan open - do not leaver against the soft aluminum.
• Once the fluid starts to flow you can carefully undo the bolts to drop one corner down more to let the fluid out.
• Once it's mostly out hold the pan up, remove the bolts (put them in a cup for safe keeping), then tip the rest of the fluid out of the pan into your plastic tray.
• Fluid will continue to drip or “rain” out for some time.

• Take the pan and gasket away outside somewhere to clean it up. In another plastic tray hold the pan up vertical with the magnet at the bottom and spray it with Brakleen back and forth from top to bottom making sure it's dissolving the fluid and gunk out of the pan leaving a clean surface. You should be-able to see the brakleen evaporating leaving no residue and a perfectly clean pan.
• Put the pan on a clean surface facing down so nothing lands or falls into it. Avoid the temptation to touch or wipe it with a cloth.

Accumulators

• First the filter has to come off, it's held on by the neck, the plastic is on the brittle side so be careful with it. It took about 5 mins to wiggle it out, I used a screw driver to apply some downward pressure where the filter neck is, and I wiggled the other end of the filter with my hand, it eventually came off. Don't leaver the screwdriver against any of the exposed parts of the transmission, and especially where the pan and seal bolt together.
• Undo the 4 bolts shown, the pipe with the rubber join will just pop out, the other two will just pull out of the accumulator with a bit of wiggling as it's removed - these pipes are made of aluminum so be careful not to bend them, or they might grab and never come out.

• When you undo the accumulator housing and remove the pistons, make a note of which one goes where, the springs are different! The 2-3 accumulator has the stronger thicker looking spring (in my case).
• The accumulator bores will be mirror smooth - the root of the problem!

• Service the accumulators by giving them a light scuff with the supplied Scotch Brite. Once done, give it a good dose of Brakleen.

Putting things back together

Try to get everything clean, and keep it clean.

The bolts that hold the accumulator together, and the 4 that bolt it to the transmission should be torqued to 97 inch pounds .

To put the new filter on, locate it and carefully tap the neck back into place with a plastic mallet.

The pan seal/gasket should be reusable if its the rubber coated steel type. Pan on, bolts in and done up finger tight, gradually tighten each bolt alternating between sides, then torque each one to 120 inch pounds, go around one last time to make sure you didn't miss one.

Just shy of 8 quarts came out. I put a full 8 back in:

Tip about 6 to 7 quarts back in, start the engine, go through the gears, check the level between putting about 1/2 a quart in at a time, until it's full, I then did a little forwards and backwards on the driveway, topped it off to full mark again, then took it for a drive, after that the last 1/2 a quart to the full 8 brought it up to about half way on the dipstick, and this is where I left it rather than crack the next bottle open.

Since the battery will have been disconnected for a while, the PCM will reset, gear shifts etc may be a little different for a couple of days until it's finished relearning.

Bolt Torque Settings

One thing none of them mention are the torque settings for the bolts:

You will need an inch pound torque wrench.

• 8mm socket and ratchet.
• 10mm deep well socket and ratchet.
• Torque accumulator bolts to 97 inch pounds.
• Torque pan bolts to 120 inch pounds.

I found the pan bolts on mine were barely tight when I undid them.