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3211  eHam Forums / Elmers / VHF Parasitics and W8JI on: March 26, 2008, 07:06:27 PM
" Besides, any good plate can take a choke! :-0 "

That was so bad that I wish I had thought of it................ </groan>
3212  eHam Forums / Elmers / TS440SAT tuner question on: March 24, 2008, 03:53:56 PM
I have a hunch the tuner is stuck in an oddball position.

You may want to connect a dummy load, switch the tuner off, then see if the rig will pump ~100 watts (or whatever is normal for your setup) straight into the dummy load. If OK, turn the tuner on to see if it can find a match to the dummy load. May take more than one try, and listen up for any sounds of mechanical oddness from the tuner...

If the tuner tunes and the transmitter is OK, then it's something specific to the RX and not something weird like a strand of wire across the SO-239.

Here's the book: http://www.radioamateur.eu/schemi/TS440S_user.pdf
The service manual: http://www.radioamateur.eu/schemi/TS440S_serv.pdf
And the mod list: http://www.radioamateur.eu/schemi/TS440_mod.zip

GL
3213  eHam Forums / Elmers / can a quad be tuned on the ground? on: March 23, 2008, 02:55:14 AM
Last I heard, SOP when trying to pre-tune a Quad or Yagi on the ground is to point the antenna straight up... As in reflector nearest the ground.

Will the tuning change after it's installed?

Yes.

But straight up is likely the best way to minimize ground effects at step ladder height.
3214  eHam Forums / Elmers / Link Antenna Tuner on: March 17, 2008, 01:44:34 PM
DX Engineering recommends an odd multiple of 1/8 wavelength for the balanced feed line on their multiband dipoles...

http://www.dxengineering.com/pdf/Multi-Band%20Dipoles.pdf
3215  eHam Forums / Elmers / Tuner shaft sonic oscillation on: March 16, 2008, 06:30:35 PM
Looked into conductive lubricants a few years back and if I recall, NoAlOx and similar is mineral oil mixed with graphite. Probably not the best choice for long term lubrication as mineral oil tends to evaporate. It will migrate where you don't want it if you get a bit too generous, and I speak from experience on that, then I remind myself that locksmith oil is a graphite lube... Might last longer. (?)

Would also consider a black molybdenum automotive grease used sparingly. Thin enough to work its way into a bearing, thick enough to stay where it should. I've had no problems with it on variable caps and such.
3216  eHam Forums / Elmers / DMM vs Analog Multimeter on: March 15, 2008, 12:15:23 PM
'Scuze the minor diversion... 40-ish years ago the Simpson 260 and Triplett Model 60 were the workhorses of the electrical trades. Considering the kit manufacturer tested a properly working sample with a DMM, best bet would be to replicate that setup as closely as possible for a proper comparison to factory spec's.

Could a Simpson 260 do as well? Sure, but there will be more circuit loading and if you know which way to compensate for the meter, no prob. There's the rub... Which direction and how much?

I've used analog meters for years, but the DMM has me so spoiled that going back is like tying one hand to my foot. Auto-Ranging and Fluke's Touch Hold feature are very easy to get used to.

As for accuracy, yeah, even a cheap DMM has the edge.

But... Sitting in front of me as I type this is an original Westinghouse Type PY-5 Portable Volt-Ammeter.

http://chem.ch.huji.ac.il/instruments/test/ammeter10.jpg

Mine is similar to the pic, but has three additional terminals in the lower right corner for volts and labeled 150, 300 and 600 respectively. The three terminals along the top edge are labeled +/-, 10 and 5 (amps). Inside the cover is a hand typed certification sheet signed by M Donnelly on September 11, 1939.

Tells me the meter is of the moving vane type and correct to 1/2 of 1% between 15 and 133 cycles AC from 10 to 35 degrees Centigrade. DC accuracy is 1% of full scale. Considering the age... I'd say that's not bad.

Resistance of the 150 volt range is 4,680 ohms, 300 volt range 9,360 ohms. Inductance of the 150 and 300 volt ranges is 360 millihenries. Let's just say this meter would not be my first choice for audio or RF work, but it was definitely "built"... By the Westinghouse Newark Works in Newark, NJ.

Bonus Points: If you had a newspaper from 9/11/1939, what would be the big story near the top of the front page?
3217  eHam Forums / Elmers / the digits 4 and 7 in analog electronics on: March 15, 2008, 11:33:49 AM
"At least metric weapons are 9mm dead on"

There has to be a better way to say that............. Wink
3218  eHam Forums / Elmers / help needed TS430S on: March 11, 2008, 08:26:53 AM
If you tune the RX across 10.5 MHz do you hear a relay click? Same thing at 16 MHz? Chances are you do, or did before you lost TX on 20.

Very likely it's a relay or filter gone bad on the TX bandpass filter board. Had that problem with an Icom. RX worked fine but no TX. I have a TS-690 which is the HF plus 6 Meter version of the TS-450 and it definitely uses relays to switch the output filters.

If you're lucky it could be as simple as a bad solder joint. If you can pull the filter board, look for a blackened solder pad under one of the toroids or relays. Clean it up and re-solder... Might do the trick. Wink
3219  eHam Forums / Elmers / www on: March 10, 2008, 10:45:09 AM
And the answer is: 2.5, 5, 10, 15 and 20 MHz (AM) plus 192.168.0.1 (TCP/IP)

The last frequency may vary depending on your ISP type and connection... Wink
3220  eHam Forums / Elmers / Low amp draw on high power on: March 02, 2008, 05:52:02 PM
In SSB the rig is capable of 100 watts Peak Envelope Power... Average power is significantly less. If you're basing the six amp figure on the analogue ammeter in your power supply there's no way the meter movement is quick enough to display transient peaks with any accuracy.

Flip the mode switch to CW or RTTY and see what kind of current it draws at full power.
3221  eHam Forums / Elmers / LM337T Problem on: March 01, 2008, 05:48:51 PM
This may not be it, but with adjustable three pin regulators where the ground reference pin is elevated via a resistor or zener, the resistor or zener should be bypassed by a smallish cap... Something like .1 ufd or so.

Try adding a cap in parallel with the resistor or zener. Without one the output can be noisy and the noise spikes might hose the regulation.

(?)
3222  eHam Forums / Elmers / ICOM 718 on: February 29, 2008, 01:44:46 PM
Mister Google tells me it's optional...........

http://www.icomamerica.com/en/products/amateur/hf/718/default.aspx
3223  eHam Forums / Elmers / Antenna in a Tree on: February 26, 2008, 03:08:50 PM
For VHF work the higher the antenna the better, the shorter the feed line the better. Somewhere between the two is a reasonable compromise.

Personally, I don't like using trees as antenna supports as they sway in the wind, grow, and one of them put me in the hospital in '95. Sure, it was a case of self defense by the tree, but still...

Here's a link you should visit: http://www.timesmicrowave.com/cgi-bin/calculate.pl

I have a 144 / 440 vertical up about 30 feet that works FB and is strapped to the chimney as that makes for a short coax run back to the shack. My "reliable" range into a repeater is about 50 - 60 miles with a few much better. FM Simplex is good for ~30 miles, good band conditions (like a humid summer night) can double that.
 
Considering that you're in a more populated part of the country than I am a similar setup should get you as much activity as you can stand.
3224  eHam Forums / Elmers / Battery Back-up on: February 25, 2008, 05:08:02 PM
Note in my previous comment that I suggested adjusting the power supply regulator to 13.8 volts AT THE BATTERY TERMINALS. This should compensate for the voltage drop across the diode...

3225  eHam Forums / Elmers / Battery Back-up on: February 25, 2008, 01:31:47 PM
On non-linear DC supplies using a 723 regulator chip a battery connected to the output while the supply is turned off can blow the chip. Been there, done that. Look at the schematic for a Lambda or similar and you'll see a reverse current protection diode across the chip output or driver transistor.

Does this relate to your supply? Maybe not... But since we're talking 10 amps it shouldn't be that difficult to scrounge up a 15 - 20 amp diode rated @ 50 vdc or better PIV and matching heat sink. Wire the diode in series with the positive lead to the battery. The diode arrow points toward the battery. Adjust the regulated supply for 13.8 vdc on the battery terminals after waiting a bit for the battery to settle, then connect the radio to the battery.

The diode prevents the battery from flowing back to the power supply during a power outage and since the radio is running straight off the battery there is no switch timing involved... The radio is running off the battery all the time. 13.8 vdc is the standard setting for a continuous float charge on a 12 volt lead-acid (gel cell) battery.

If you have an old computer power supply on hand you probably have the parts. It's just a matter of recycling a diode and heat sink...
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