View Full Version : Bad Antenna Tuner?
Here's an interesting eBay find (http://www.ebay.com/itm/Tech-Special-Ten-Tec-Model-228-Antenna-Turner-/120948670590?pt=US_Ham_Radio_Transceivers&hash=item1c291a407e)—a Ten Tec antenna tuner being sold as "Not working or for parts" because the seller can't get it to match any of his home brew antennas.
Since there's not a whole lot that can go wrong with an antenna tuner you have to wonder if the problem lies more with his antennas than the tuner, although I suppose there could be a bad diode in the SWR meter that's causing him to think there's a problem elsewhere.
KC2UGV
07-12-2012, 11:08 AM
Here's an interesting eBay find (http://www.ebay.com/itm/Tech-Special-Ten-Tec-Model-228-Antenna-Turner-/120948670590?pt=US_Ham_Radio_Transceivers&hash=item1c291a407e)—a Ten Tec antenna tuner being sold as "Not working or for parts" because the seller can't get it to match any of his home brew antennas.
Since there's not a whole lot that can go wrong with an antenna tuner you have to wonder if the problem lies more with his antennas than the tuner, although I suppose there could be a bad diode in the SWR meter that's causing him to think there's a problem elsewhere.
I'd buy it in a heartbeat. It's like you said: there's not much to go wrong in a tuner. And, I'm guessing it's the antennas.
kf0rt
07-12-2012, 11:15 AM
That tapped inductor thingy looks like it may have seen some heat.
That tapped inductor thingy looks like it may have seen some heat.
Yeah, maybe. Interesting design, though, using a toroid as a variable inductor in an antenna tuner in that way.
EDIT: Looked at it more closely, the insulation is melted on one of the wires that passes close to the inductor. I think you're right.
ab1ga
07-12-2012, 11:28 AM
That tapped inductor thingy looks like it may have seen some heat.
Do you mean the inductor parallel to the front panel? What looks like discoloration on the panel may actually be a reflection. I don't see anything that got hot enough to cause the insulation to creep back from the end of the wire, either.
If there's anything wrong with that tuner, it can't be an expensive fix. I agree with Corey, pull the trigger on it.
73,
Look at the knobs on that thing, will ya!
Look at the knobs on that thing, will ya!
Hey, you can't say "knobs!"
I'd buy it in a heartbeat. It's like you said: there's not much to go wrong in a tuner. And, I'm guessing it's the antennas.
If it's not and you need a part, chances are I have one.
kf0rt
07-12-2012, 11:36 AM
Do you mean the inductor parallel to the front panel? What looks like discoloration on the panel may actually be a reflection. I don't see anything that got hot enough to cause the insulation to creep back from the end of the wire, either.
If there's anything wrong with that tuner, it can't be an expensive fix. I agree with Corey, pull the trigger on it.
73,
Yeah, the toroidal thing. It looks like it's wound on a plastic core and the plastic is melted (around the finger at the top). Some heat (?) discoloration on the wire too, but the picture isn't clear enough to tell what shape the wire is in.
I'd agree with pulling the trigger (after I checked Ten Tec's parts supply for that inductor). Looks like a custom part.
X-Rated
07-12-2012, 01:58 PM
Even if the plastic is slightly melted, I can't see how that would cause too many problems unless the tap doesn't make contact somewhere.
WØTKX
07-12-2012, 03:54 PM
Unless the core is fused/cracked. It happens with that ferrite stuff.
Unless the core is fused/cracked. It happens with that ferrite stuff.
Looking at the pictures again, I don't think anything on the inductor is damaged. What looks like melted plastic looks to be nothing more than electrical tape wound around the ferrite toroids to keep the bare wires from shorting out.
However, there does appear to be evidence of possible arcing from one of the wires leading from antenna selector switch to the left hand tuning cap.
ab1ga
07-12-2012, 06:40 PM
That could be explained by some fool trying to match an impedance outside the range of the transmatch. A bit of TLC, plus knowing how to use a transmatch, should fix that.
That could be explained by some fool trying to match an impedance outside the range of the transmatch. A bit of TLC, plus knowing how to use a transmatch, should fix that.
"I think we're gonna need a bigger boattransmatch!"
K7SGJ
07-12-2012, 06:45 PM
"I think we're gonna need a bigger boattransmatch!"
Well, you have to expect a few sparks when trying to tune a couple of kilowatts into a pickup truck bumper.
KA9MOT
07-12-2012, 06:50 PM
Is that a vernier dial on the front? It isn't stock whatever it is.
n2ize
07-13-2012, 03:10 PM
I'll stick with a Johnson Matchbox. The thing will match anything to anything. I could load into a fire escape or a radiator with the matchbox..
WØTKX
07-13-2012, 04:12 PM
Well, within it's range it will. I've had good luck with bigger MFJ's and a Dentron Supertuner
I try not to load up truck bumpers with QRO.
I'll stick with a Johnson Matchbox. The thing will match anything to anything. I could load into a fire escape or a radiator with the matchbox..
Every tuner, no matter who made it or when, will have some combination of settings that will create smoke on some band.
KG4NEL
07-13-2012, 05:02 PM
Every tuner, no matter who made it or when, will have some combination of settings that will create smoke on some band.
From what I've been reading with the kW Matchbox, it's the WARC bands...and 160, but that wasn't part of the design.
KG4NEL
07-13-2012, 05:05 PM
I tried pricing out building my own QRO tuner for a full-wave loop a few months ago, and got discouraged. Whether L or T network, getting both a decent matching range on 160 without taking 10 meters out of the equation is tough (read: "expensive") to do. Those big vacuum variables and roller inductors aren't cheap :(
I may farm the project out when I get an amp...or just buy a Palstar, lol.
kf0rt
07-13-2012, 05:18 PM
I tried pricing out building my own QRO tuner for a full-wave loop a few months ago, and got discouraged. Whether L or T network, getting both a decent matching range on 160 without taking 10 meters out of the equation is tough (read: "expensive") to do. Those big vacuum variables and roller inductors aren't cheap :(
I may farm the project out when I get an amp...or just buy a Palstar, lol.
Got a Palstar AT1KM here. Take that thing up in the mountains and hang a random length wire in the trees, you can work VK/ZL with 20 watts on 40 meters CW. Nice unit. :) Real roller inductor.
KJ4FEL
07-13-2012, 05:50 PM
Every tuner, no matter who made it or when, will have some combination of settings that will create smoke on some band.
Don't I know it! I managed to let the magic smoke out of a LDG IT-100 Auto-Tuner :)
n2ize
07-14-2012, 09:18 AM
Every tuner, no matter who made it or when, will have some combination of settings that will create smoke on some band.
True, but there isn't a whole lot to make smoke in a matchbox. I've done some things with a matchbox that would have easily zorched most turners and the matchbox didn't even arc over didn't even get warm. Haven't managed to smoke one yet.
True, but there isn't a whole lot to make smoke in a matchbox. I've done some things with a matchbox that would have easily zorched most turners and the matchbox didn't even arc over didn't even get warm. Haven't managed to smoke one yet.
Give me one—I'm sure I could manage it.
I tried pricing out building my own QRO tuner for a full-wave loop a few months ago, and got discouraged. Whether L or T network, getting both a decent matching range on 160 without taking 10 meters out of the equation is tough (read: "expensive") to do. Those big vacuum variables and roller inductors aren't cheap :(
I may farm the project out when I get an amp...or just buy a Palstar, lol.
Scrounge your local neighborhood hamfest. I was getting air variables with 25KV plate spacing for $10-20, 2+ KW ceramic band switches for a buck...
KG4NEL
07-15-2012, 06:45 AM
I already missed one this year, so that leaves one more to go for the year :D
Besides, I really don't have the tools to do a decent job of it, fabrication-wise...I could hand drill the case, but it'd look like I got into the whisky before I started...
Don't know if you've seen these guys or not. NOS parts, and decent pricing if you're QRO
http://qro-parts.com/
Besides, I really don't have the tools to do a decent job of it, fabrication-wise...I could hand drill the case, but it'd look like I got into the whisky before I started...
A hand drill is really all you need to do a passable job. Take your time and lay things out beforehand. I wonder if we could talk Bob, VK3ZL into doing up an "Equipment Cabinet Construction Basics" thread - all of his stuff is handcrafted and looks commercial quality.
Don't know if you've seen these guys or not. NOS parts, and decent pricing if you're QRO
http://qro-parts.com/
I put that one in the "Parts Sources" sticky. Thanks Doug!
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