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eHam Forums / Antennas and Towers and more / High Power Remote Tuner?
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on: October 16, 2012, 09:04:42 AM
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Hello, In my endless search for ham radio perfection, I am thinking about remote tuning. The station antenna is a 5BTV ground mounted up the hill behind the house. It has approximately 50 radials ( actually, I lost count  . I have made many many trips up and down that hill ( oh my aching knees ) setting up and tuning that antenna, and it works pretty well. I use a Heath SA2040 in the shack to touch it up. Sure would be nice to have some sort of tuner out there with the antenna, and not separated from it by a hundred fifty feet of coax. Such a tuner would have to be either automatic or remote controlled. It would have to tolerate the full 1.5kW. Looking at commercial offerings, I see the MFJ998RT - which seems to be a bit of an abortion. They took their desktop autotuner and stuck it in a weather box. So there is no remote control available at all. The only control available in the shack is turning the power on and off, and piping RF up to it. Under the hood there is an interface consisting of a couple of buttons and a small LCD display. So any setup has to be done at the antenna. I suppose it wouldn't be TOO hard to make something with a little video camera ( to watch the LCD ) and a couple of wires hooked to the pushbuttons. Or I guess I could just build something. I'm reasonably good at electronics and firmware programming..... Not sure if I want to work quite that hard though . Maybe put the SA2040 in a big box with three screwdriver motors? - Jerry, KF6VB |
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eHam Forums / HomeBrew / RE: Farewell to Hethkit
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on: June 17, 2012, 10:03:14 AM
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And here's the Big Challenge:
Say you woke up tomorrow and it was 1962 [...]
What, exactly, do you do?
*** Umm, buy some stock? What was hot in the 60's? Maybe HP or Tektronix. And didn't Lockheed make a lot of money off the space race? If it was 1970 or so, I'd buy Intel. 1980, Apple. - Jerry Kaidor, KF6VB |
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eHam Forums / Amplifiers / RE: PSK with 30L-1?
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on: June 17, 2012, 06:54:44 AM
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A 5BTV pounded into the ground is not going to perform well on any mode. You need ground radials, not just a single ground rod. Not true I have used one for many years and is does a decent job. PSK31 is meant to be a low power mode, 30 watts or less. No need for anymore power than that. Most times this is quite true but there are times when even 100 watts is not enough. The reason most run low power is also because rigs get quite warm during transmission as it is basically constant key down. Fix your antenna and run 30 watts. I have never run anymore than 25 watts on any digital mode other than RTTY and Hell.
Again conditions is a factor too at times. When there is not propagation you are not going to make contacts with 1000 watts. We all know that. However I have never had to run more than 30 watts on PSK31. If conditions are not right you will not make contacts. IMO using an amp for PSK31 is inconsiderate of others using the frequency. *** OK, the antenna was crappy. I fail to see how running high power with a crappy antenna is less "considerate" than running low power with a good antenna. It's the same RF at the other end. Since then, I have been gradually adding radials to the system. I also moved it up to the top of my hill. So I probably won't need the high power any more. - Jerry - Jerry Sure a trap vertical will work without radials. But a dummy load works too. We all know that radials are the 2nd half of a vertical antenna. You state your vertical does a decent job? So does a G5RV at 15, friend of mine has to use his at that height. But we all know it would work better at 55 feet. |
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eHam Forums / Amplifiers / RE: PSK with 30L-1?
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on: June 17, 2012, 06:51:33 AM
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Hello,
After being off the air for about 12 years, I'm back. Pulled my 30L-1 out of storage, cleaned it off, vacuumed it out,
washed the tubes in running water, cleaned the switch contacts, oiled the fan, brought it up with a Variac over about a day. All OK. Did you have it stored in a mineshaft? Why so dirty to need a bath??? *** There was dust "stuck" to the tubes that would not come off with just blowing and vacuuming. So I rinsed it off. Just the tubes, not the amp. Everything else I cleaned with vacuum and blowing and a little brush. - Jerry |
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eHam Forums / Amplifiers / RE: PSK with 30L-1?
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on: June 15, 2012, 08:11:11 AM
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PLEASE do NOT run more than 30 watts on PSK - that will just about wipe out the band!!!
*** I don't see why. 500W is about 12db more than 30W. Make that 4 S units. Would it be more socially acceptable if I ran 30W into stacked Yagis? Point them at you, it's the same 12 db. As far as "wiping out the band" is concerned, the important thing IMHO is to keep it clean. Don't overdrive anything. Try not to see any ALC reading. Nowadays, everybody has waterfall displays, and they can see when you splatter all over the band. - Jerry Kaidor, KF6VB |
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eHam Forums / Amplifiers / RE: PSK with 30L-1?
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on: June 12, 2012, 08:22:40 PM
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If others can't copy you if you are running 20 watts on PSK31 then you better take a good hard look at your antenna system.
A 5BTV pounded into the ground is not going to perform well on any mode. You need ground radials, not just a single ground rod.
*** So far, I have 6 radials on 20, and two on 40. Whenever I have a spare moment, I go out there and add
a few radials. I got a 500-foot roll of 14-gauge, that's almost enough for 30 radials. True, when I was trying
PSK, I didn't have any radials at all. Ought to give it another try.
I found a guy in the eham reviews of the 30L-1 who's running 600W on RTTY with his 30L-1. All he did was
replace the tubes with 572B's and lay a muffin fan on top of the box for contests.
- Jerry Kaidor
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eHam Forums / Amplifiers / PSK with 30L-1?
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on: June 12, 2012, 06:36:35 PM
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Hello,
After being off the air for about 12 years, I'm back. Pulled my 30L-1 out of storage, cleaned it off, vacuumed it out,
washed the tubes in running water, cleaned the switch contacts, oiled the fan, brought it up with a Variac over about a day. All OK.
PSK is a new, fascinating mode on the bands. It works with my computer sound card. It's like a whole ham band in the space of a single SSB signal. With a relatively modest antenna ( 5BTV vertical ) pounded into the hillside behind my house, many people cannot hear me.
So I tried QRO... according to data on the Net, PSK is not especially efficient WRT really low signals - it's just a bit better than RTTY. Just like SSB - people can't hear me, push the big switch on the 'L-1, and suddenly they CAN hear me.
But the 30L-1 is definitely not happy with that mode. Even running reduced power, it gets really hot. I gave up
on that. Maybe it's time for a new linear. There's a local guy with a fair deal on an Ameritron AL-80B. Pop goes the egg money!
Or maybe the 30L-1 could be modified? I can get a matched set of four Chinese 572B's for $200 from IIRC RF Parts. And then maybe paint the inside of the final cabinet flat black for better infrared heat transfer? And keep the power down to maybe 300W? Anybody out there doing RTTY or similar with a 30L-1?
- Jerry Kaidor, KF6VB
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eHam Forums / CW / RE: First CW QSOs
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on: May 07, 2012, 08:48:14 PM
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[ Always found it easier to copy
code groups than conversation or text. Stuff with actual meaning would distract me, and I'd miss a bunch of characters.
This normal for former military radio operators or intercept operators. [/quote] *** Or for hams who got their license a long time ago. In my case, around 1970. Back then, the cw tests were all done with code groups. You had to go down to the FCC office ( in my case, the Customhouse in San Francisco ). They also made you send. It was an experience. Exciting, isn't it? *** Yes, it is. Code is beautiful. It's like music. - Jerry, KF6VB |
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eHam Forums / CW / First CW QSOs
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on: May 06, 2012, 08:58:44 AM
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OK, Had my first CW QSO in 20 years the other day. Nothing special, lasted about 5 minutes. Sweating like a pig. Concentrating hard enough to cut diamonds. XYL asked me something, and I snapped at her . I never was that good at CW. Managed to pass my extra in 1987 by dint of computer practice. Always found it easier to copy code groups than conversation or text. Stuff with actual meaning would distract me, and I'd miss a bunch of characters. This morning, I found out something interesting - in the context of a contest, I can do over 20 WPM! Because very little actual information is being sent. I QSO'd a 2 and a 1 ( New England QSO Party ). Their names were both "5NN" . All this scribbling is hurting my fingers. I need to learn to mill-copy. - Jerry Kaidor, KF6VB |
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eHam Forums / Remote HF Station Control / RE: HF Rig control of streaming audio server
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on: April 27, 2012, 02:45:09 PM
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I recently set-up an audio stream of my father's HF rig at his house over the internet. (MMS://w5cqu.homeip.net:8000/hf) That was fairly easy using a Linux server and Ice-cast/DarkIce. But, I wanted to take it one step further and allow him to remotely control the frequency and mode of the rig using a web browser on a PC or mobile phone (specifically, iPhone). I have come up with the following solution that I will attempt to describe in case anyone would like to do this also. *** Wow, this is excellent! Thank you so much for posting the details. Ever since the early 80's I have dreamed of being able to ham from any room in the house, and this could definitely do it. And as it happens, I have spent a great deal of time over the past 5 years writing perl/CGI code. This just begs for AJAX ( Asynchronous Javascript And XML ) - for things like animated knobs and meters. - Jerry Kaidor, KF6VB |
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eHam Forums / Remote HF Station Control / Icom interface cables on Ebay
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on: April 26, 2012, 08:22:22 AM
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Hello,
I have an IC706MKII that I'm interested in remoting. Basically, I'd like to be able to ham from any room
in the house. But it needs a computer interface. Prferably USB. I see there are people in Hong Kong selling these things for $9 including shipping. I imagine they contain an FTDI chip plus the necessary wires and connectors, and not much more. Has anybody tried them?
- Jerry Kaidor, KF6VB
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eHam Forums / Elmers / RE: Measuring Complex Impedance of a Toroid
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on: April 25, 2012, 12:23:14 PM
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If I read this correctly, you are measuring the real (resistive) component of a two turn winding on a core. Well, two turns will have very low R component, not much higher than the ohmic R at DC. What is the reactive component (L)?
*** I wouldn't expect to see much resistance. Look at it this way - any resistance at all is power that you're putting into the coil, and that it is absorbing. Current in phase with voltage. Such power absorption could only come from: * ohmic losses of the wire * Low Q or inefficiency of the toroid material * radiation resistance - to some extent, your little coil is an *antenna* and power is coupled to the ambient environment. Of course, this is minimized with a toroid core. - Jerry Kaidor, KF6VB |
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eHam Forums / CW / RE: Practical Morse
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on: April 21, 2012, 11:29:12 AM
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Being a programmer, I'd have gone for something in binary
*** One coworker asked why I didn't bit-bang a serial interface:
Yet another thing to troubleshoot. You get it wrong, the terminal either just sits there or displays gibberish. Then you haul out the scope to look at the pulse train.... You also have to get the pinout and voltage levels
right. With the morse thing, the total hardware consisted of a baby speaker and a resistor. The time from
getting the idea, coding it up, wiring it up, instrumenting the code, recompiling, burning a rom, running it
and figuring out the problem was literally just a couple hours.
- Jerry Kaidor
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eHam Forums / Antennas and Towers and more / 4BTV capacitive hat
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on: April 21, 2012, 11:15:45 AM
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Hello,
Many many ( many! ) years ago I bought a Hustler 4BTV vertical at the flea market. Didn't have an immediate use for it, and it laid around for 10 or 15 years. Now I have moved, and I have a definite & immediate use for this antenna. I spent the morning cleaning all the aluminum junctions. Unfortunately, I can NOT find the fingers for the capacitive hat. I seem to remember them being 8 or 9 inches long and maybe 1/4" diameter aluminum rods or tubes, with a screw and nut ( probably brass ) at the end.
Anybody have precise measurements for these capacitive hat fingers? I do have the collar.
- Jerry Kaidor, KF6VB
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eHam Forums / Boat Anchors / RE: SB34's
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on: April 19, 2012, 08:57:30 PM
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Possible solution for that involves exercising a trimmer condenser... *** Thanks! I just did that, and it really helped. No more sudden wanderings. No, I didn't use DeOxit. Just marked and twisted - exactly 12 times in each direction . - Jerry Kaidor |
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