The AM Forum

Hello Fellow Amers
Looks like Murphy is still around the house!! I discovered last night that my wonderful Bliss Mat Master Tuner is not happy. It took an hour and a half to disassemble the Dam thing. Ole' John Bliss didn't want anybody to figure out how he obtained a truly balanced system using two coils. The coil winding have come loose and it's destroying the finger stock on the one side and there has been some heating on the other side so there are windings touching each other.
 
Anybody have a suggestion for a replacement tuner........balanced......NO 4:1 BALUN on the outpoot???? High power, wide range, low loss on 160M. I can check ARRL product reports.

Additional Bandwidth: The design of the Bliss tuner was unique. He has two indentical coils mounted on a single coil form. Through some maze of mechanical wizardry he slides these coils back and forth and there is fingerstock surrounding the coil form on both ends that short out whatever is needed for the tuning process. There is a nice vac cap in there also and small knife switch to switch the cap before or after the coil.
The pix should tell it all
Any advice from my radio buddies???
thanks
Fred

Fred;

Homebrew the Richard Measures balanced tuner. Lots of folks have built it and are using them sucessfully.
Uses a pair of roller inductors. I don't have the link handy, I'll see if I can find it later today. I'm sure someone will chime in on this one. Pretty sure Joe N3IBX and others here on the list have built them. Supposedly, the Bliss tuner is based on the Measures design but after seeing your photos, and doing a little reading, it is apparently different and doesn't seem to be as robust as a homebrew construct of the original design,




 

Here is a link to the tuner info;

http://www.somis.org/bbat.html

The tuner you have looks hard to beat once you fix the weak links. Pardon the pun. That style tuner and the Measure's design don't  really need a roller inductor. You can homebrew pairs of coils from copper tubing to save cost and hassle looking for the parts. Inductors can be matched using a dip meter, MFJ antenna analyzer or inductance bridge. Tap the coils every turn and use a ceramic switch setup to short the unused coil. To go even one step cheaper, construct the tuner with no coil taps and just figure them out after installation. Solder lugs onto the taps and switch them when needed. I have one tuner that happily works on 2 bands without changing the 2 coil's inductance so the taps are fixed. I switch to a second tuner with roller inductors when going to other bands.

OK Fine!
Thanks for the replies.
I have made temp repairs on the loose windings. I cannot repair the shorted windings from whatever meltdown took place. John Bliss thinks he can scrounge up a replacement coil for me. All he makes now are motorized versions of these tuners and MAN.......are they expensive!!!! The PalStar tuners were highly rated but some unhappy Hams for some mechanical problems. I know you builder guys are wondering why I don't build one. Lazy??? I'll go out and buy all the components new from $urplus $ales of Nebraska??? My junque box stinks.

I also moved the tuner to the wall where the LL comes in and cut off about 30 feet and the tuner gives indication of working now. Almost 1.5:1  match at 1820 and 50 ohms to the Radio side. The first effort to light up the station was  2:1 SWR and 35 ohms on the radio side.  I will test during Dead Band conditions during the daytime to see if the system can take power without meltdown.
Fred

That's a great Idea Dave... but if you experiment a lot with different antennas, you may have to move those taps around when you put up a different ants as you mentioned (you'll need a lot of switch positions to put a tap on every turn) although I do like the idea of using copper tubing for a pair of coils instead of the roller inductors...

Fred, no need to buy from fat wallet sales of Nebraska, get the copper tubing cheap from your local Home Depot and buy the variable caps used on E-bay. A vacumm variable is nice, but not necessary. All you need besides that will be a double pole rotary switch, also available cheap on E-bay.

Being thrifty can take extra time! Those tuners take extra patience to figure out settings. It can be especially frustrating without some test gear! I used to have a JSed one here for 160 that had many hours of Edison guess and guess again engineering. This included cooking many TV type capacitors and a few coils. I'd stick with the vacuum variable as the tuner will then have the ability to feed power very close to Voltage nodes at it's output. You can load a wet noodle or a farmer's fence. Who knows where the power goes but it does get transferred to the load!

Fred,
Take that vacuum variable, get some 1/4", 5/16" or 3/8" copper tubing to coil and mount them on a flat aluminum plate. Mount it on the wall. You will have a great tuner.

See the details below:

http://amfone.net/ECSound/K1JJ13.htm

I've built five of these and they work FB. Only needs a single ended vac cap, like you have, and 30 turns of copper tubing that can be accessed via big copper alligator jaw clips.  Have the taps premarked to switch bands 160-10M in seconds.
Match ANYTHING.

Be the first on your block. Amaze your friends. Be the talk of the neighborhood. Outstrap Brentina.

I can send you a FAX schematic of it if you are serious and cannot understand the written description in the url above.

T

Getting back to Fred's original post, there must have been several complaints about that tuner. Tom Hix, W4TH who mostly sells Russian tubes, used to sell and shill for Bliss. He even had a link to Bliss's website. Now there isn't even a mention of the tuners. I agree with Mr. Vu, the best ones are the home made ones. Look inside those MFJ 'things' and prove that there is a fool born every minute. Even the Ten-Tec's are pretty wimpy.

Fred's original post says.... "Anybody have a suggestion for a replacement tuner"

Build it youself Fred, as I mentioned before, Home Depot is your friend... the ham's motto... "cheap, cheap, cheap".... A big ass air variable will do just as well as a vacuum variable. Clips are cool, but get a nice high power ceramic rotary switch and you won't have to screw with the clipy clipy dance.  ;D ;D

The good thing about using four giant copper alligator clips is that you can tap either the capacitor OR feedline to the 40 different coil taps. This turns out to be hundreds of possible combinations, so that once you find the PERFECT four tap positions for each band, you can premark them and switch instantly.  You can match anything from max voltage to max current peaks on the line.

Using a pair of tiny 6V bulbs, one for each feeder wire, you can also tap in or out a turn on the coil to bias one side that has a slight inbalance - and get the lights [or current meters] to compensate the antenna's imperfections. I found that many antennas I thought were perfectly horizontal had slight inbalances for whatever reasons... different ground across the antenna's path, openwire nearer one thing or another.... and it was different for each band.

With the tuner I mentioned above, the four clips are equivalent to a rotary switch with about 165 different positions.... ;D  Either way is FB, but I like simple with the minimum amount of parts and max flexibility.

73,
T

Hello again,
Has anybody built the tuner that Tom K1JJ mentioned several posts up??? I would like to see some pix of the beast. A picture is worth a 1000 words to me. I read the link Tom gave and it's not getting through my retired brain cells.............sorry.
I don't have FAX and Tom doesn't have a scanner.


73            Fred

I've been using the balanced measure's tuner since I built it in '83 about 7 years before Rick discovered it. I have a pair of 22 UH 5 KW rollers and a pair of 300
pf 10 KV Cardwells. A Vacuum cap would work fine.You could use 2 tapped inductors or do the tom vu thing. Commecical stuff is mostly crap. Stay away from anything having a balun on the OUTPUT  because is is lossy junk! The balun belongs on the 50 ohm side of the network.

I could FAX the schematic to anyone who could scan it and post.  Anyone have the capability out there?

The tuner is just a single section variable - floating. It is across a 40 turn copper tubing coil.  There is a 5 turn 50 ohm link wound inside or outside the big coil that connects to the rig and goes to ground.

The feedline taps onto the coil, evenly spaced, and the capacitor clips to the coil, evenly spaced.  That's it.  Infinite tap combinations to match anything.

I don't have any tuners left here to take pictures of anymore - went to all hardline/coax. But there's been at least six guys that I've emailed with from this BB over the years who have built them. Maybe one of them will have a pic. But, with the schematic, you can't miss Fred.  Worst case, I'll Fax it to your work QTH.

T

HOPE THIS WERKS...TIM...SK..

Thanks for posting it Tim!

Did you ever build it up?


Here's the handwritten notes I made so that you can read them:

1) Add a variable ~1400 input cap if needed in series to ground with the 50 ohm input link. Most guys don't bother.

2) Big coil is 40 turns to cover 160M. Less for 75M. NOT critical. Any coil will work if it has enough inductance. The bigger tubing diameter, the better for losses. 1/4" - 3/8" is FB.  6" high X 15" long is typical.  Wind it on a quart paint can as a rolling  form and suspend on stand off insulators. [remove can... ;D] Many ways to do it.

3) Solder copper strips onto coil for EZ access with big copper alligator clips, and pre mark for fast QSY to bands.

4) Move around the taps of these four spots to achieve a perfect match on any band in conjunction with C1 variable tuning. Keep both open wire taps and capacitor taps equal spaced from coil ends. [ symetrical - balanced]   The taps can be anywhere, as long as balanced.

5) Move one openwire tap in or out one turn to achieve equal feedline balance as shown by tiny bulbs or RF meter current if desired.

6) Both C1 and big coil float above ground. Use insulated shaft/knob since RF voltage is on the capacitor shaft.

7) 50 ohm, 5 turn  link is suspened inside, outside or on top of center of big main coil.  Use Teflon insulated wire if it touches main coil.  #12 wire is OK for link or whatever the diameter of your coax inner wire is. Some use copper tubing because it is easy to support inside big coil. It can be a smaller coil inside and still get good coupling, but keep the coils within an inch or so of each other's diameters. Facing the same plane, of course.

8) Use input SWR meter to adjust the taps and C1 for 1:1.

73,
Tom, K1JJ

SAVE THIS PICTURE TO YOUR DRIVE AND THEN BLOW IT UP BIG to VIEW.

..TOM..GOT ALL THE STUFF FER IT,GOING DO IT SOON....BTW,THERE IS A SEPARATE SECTION,IN THE FORUM WHERE THIS COULD BE STORED,FOR OTHERS TO VIEW IT,ISNT THERE?..TIM...SK..

Sorry, yes, I should have mentioned to use the clips to find the correct positions,(initial setup)  THEN install a switch..... My brain no work too good.... no sushi this past weekend!  ;D ;D

Hmmm... not a bad idea, Glenn!

I never thought of installing a large, 4 pole, 6 position switch to do the job after the taps are optimized. It wud work and be very fast.  I'd like to see someone do it.

The switch wud have to be a good sized one with both heavy contacts for current maxs and wide spacing for the voltage peaks that will randomly be found across the various bands. That's assuming a KW.

Once the switch is installed in place, the leads going to the various coil taps cud be soldered in a way to be easily moved as antennas and requirements change. It certainly wud be something to look at once finished with 24! various leads for 6 bands. 

In my case, I simply built five different tuners that hooked to various antennas to be instantly switched at the 50 ohm coax input.

T

OK Guys,
Thanks for the posting of the scheezo. A Pix would help me to assemble the components better, but let this be a challenge for me to get the mechanical part configured so that it doesn't look like an RF nighmare. I have a lot of those nice ceramic insulators that can be used and I'll mount this tuner on 3/4 inch plywood.
See youins on 160 tonight????


73        Fred

Hello Guys,
The Bliss Tuner is definitely sick, I can hear a little fizzle inside doing dead band testing. So, the JJ tuner starts construction soon.

My + noise level has disappeared since I moved the tuner to the outside wall where the LL enters into the house. Running long lengths of LL around house wiring, even though is seemed spaced far away, or any where near flourescent lights may have been giving me my evil noise problem.

Now the IF strip in the 390A has an AGC problem. Dam!!! when can I start using this stuff instead of fixing all of the Murphy crap????

Getting a little worn out I hope I NEVER move again!!!
Fred

Hmmm... normally, the open wire line will cancel and be balanced, so you shud not be picking up any stuff like that.  Perhaps there is an inbalance in the system. When you get the new tuner going, try the old 6V bulb test with one on each feeder leg, set at low luminence to see if they are the same brightness. If not, then we can talk about it.

Build the tuner and you will learn a lot and have total control over all parameters of the feeding.

73,
T

Fred said:
I feel your pain Fred. I moved and have a sick Valiant blowing fuses when keying, a Viking I with a LVPS transformer heading south, and a DX-100 with a bad fuse holder! I got so fed up I managed to find a new fuse holder, got my soldering gun, (couldn't find the Weller iron), and used my fingers as needle-nosed pliers to do the soldering. Now I can't find the front panel for my electrical sub. Parts and tools are here and there, and it seems anytime I need something, I have to go on a nature hunt to find it. What really sux is you saw where you put it but can never remember where when you need it!

...mike,..that's why i have probably the largest collection of screwdrivers,and pliers...cant find them,so i go and but more,then lose those...when i become a SK,and the estate is cleaned-out,someone will find a massive supply of hand tools...sk...

I'll play the newbie and ask: What value for C1? ???

Whoops, I forgot to mention it.

Well, it depends if you want to cover 160M or just 75M as the lowest band. For 160M I wud suggest about 300pf or so. For 1500W I wud also suggest a 4-5kv capacitor spacing.  1/4" minimum. An old BC-610 cap with the two sections in parallel wud make a great cap. Or, a vacuum variable that's the common 500 pf at 7-10KV is even better.  Remember that only a single section is needed, so makes the choices easier. Remember to mount the cap on standoffs and use an insulated shaft for the knob. The coil also gets mounted on standoffs and floats.

You will find that with the four alligator clip choices, you can match about any load. The 50 ohm link tuning cap is a nice addition if you find you have wide ranges of various antennas, tho it is often not needed cuz of the versatility of the four variables and the cap tuning.

Dave, W2APE is building one up. He does real nice work and will hopefully post a picture of it.

They are so simple and require so few pasrts, I really like the idea of having a few pre tuned and connected to various antennas. Quick band hopping.

A good system might be a 160M open wire fed dipole that uses one tuner- used on  75M too.  Then a 40M openwire dipole that uses another tuiner- use on 20M too. And finally an openwire dipole for 15M that covers 10M and  6M.  The idea is that the antennas wud show a nice pattern [figure 8] on both bands and be easily tuned to either band. A coax switch cud get you on the next antenna/system. Fast.

I can envision having them preset on your favorite bands, like 75M, 40M and 10M ready to go with a coax switch.

T

FB, Tom...I've added this to my "reference library." ;D  Thanks.

GOOD BYE BLISS TUNER,
Hello my friends
I just wanted to say that the K1JJ tuner really does work!!!. I'll take a pix and you can see. Not the prettiest thing around BUT it plays very nice. Very slight warming of the coil. It was a breeze to find the 1:1 match using the MFJ 259 for 160,80 and 40M. Able to get 50 Rs and a Xs of 8.
 40M was a long time finding, but it handles legal limit with no arcing. The 40M taps were :::::Feedline, last taps in center of coil and the Vac cap 1 tap behind the feedline. Like I say,  full power and no arcing. I'm in heaven.

NOW the damned T/R relay crapped out on receive. It's a high power Magnecraft used in a Motorola FM base. I guess the contact was fryed from lightning in it's 2-way FM days at my former place of work.
Thanks for all the help a Pix is coming tomorrow.
Fred MOP radio

Fred,
 you worked for Mot? I did also for the worst year and a half of my working life. There were two possibes ways to get termianl sick working for them. 1. Mouse piss. 2. Terminal JSer's disease

Wonderful....wonderful...  as Laurence Arc used to say.

That's good news, Fred. You now can see the joy of total versatility and control of a perfect match. Now that you've found the right taps, put the little bulbs on the feedline legs and fine tune each feeder leg in or out a turn to get equal brightness. Use low intensity for better eye sensitivity.

Once you get these coil taps marked, you can change bands in seconds.  Welcome to a small group of guys who have built and are using the tuner... and congrats on doing it homebrew, OM!

Can't wait to see the pic of your own implementation.

73,
Tom, K1JJ

How I remember my parents watching those distorted black and white TV pix and the 4kc audio from the networks. The bandwidth hog was the video, even though sent by "coaxial cable" through the telcos or microwave, the audio was telephone quality from the networks, EVEN if the show originated in the city where you lived. Everyone heard the same crap.

OK on some bulbs to balance the system. Thanks for sharing the diagram and the "white paper"

The pix are the inpoot coil, which was a nice ceramic job laying around, I guess 3 inches and 6 turns. The beaded stuff was stolen from the Bliss tuner inpoot circuit. It gets very warm for an old buzzard.

The last pix is the actual tuner in all of its glory. Gotta find a better way to clamp onto the taps. I had some clamps from an edgewound coil. The local home store didn't have any manly aligator clips.
G'day..............MOP radio
Fred

Sorry,Here's the inpoot pix
Don't know what happened

fred

Looks FB, Fred.

Please explain about the "Beaded" thing from the Bliss tuner??  You want to use regular wire for the input leads. You don't want to choke anything off there. You say the beaded lead gets warm????  Maybe I misunderstood.

Try to score a turns counter for the vac variable and pre mark a little card with settings. EZ and FAST.

Looks like you laid it out right and should work FB, OM.

T

OK Tom,
I was just copying the input circuit from the Bliss Tuner. It was the length of coax you see that connected to the "built-in" wattmeter. It's a number of the small iron cores you see there. I cannot figure out what this is for, just threw it in coz it was on the Bliss tuner. Maybe someone can figger what is going on. Would it be like a 1:1 un-un??
Just throwing something out there. You know, empty barrels make a lot of noise.
The tuning of the variable is mainly 3/4 full PF for 160M and 80M and almost no PF for
40M.
I'm gonna nail things down and mount it on the concrete wall later today

Fred

...fred...the input coil..is it just sitting in there,or bonded in place? btw,how much copper toobing did ya use?..tim...sk..

Fred,

Yes, take those ferrite beads off the coax. You see, normally they wud be OK, but in this case, they are inside the main coil and are heating up due to coupling energy from this big coil.  Remove them and you're OK.  If you want them, then use them OUTSIDE of the big coil, at least a foot away.

The 40M taps being close to the inside... that's a pot luck thing... so happens that you are near a current max and are feeding it low impedance by tapping closer to the center. You can always add 10' or so [or subtract 10'] from the total feedline length, and hope that the other bands stay nicely positioned at the same time. When running one tuner configuration like that, there is always one band that is right near the voltage or current max... probability. Find a way to lengthen the feedline somehow while still maintaining a nice fedline run and your problem will be solved.

Another possible way is to JS clip lead in a 1200 pf cap in series with the input link to ground for a test. Try various settings of that. This will alter the transformation ratio and may let you get away with bringing the taps out a little more on 40M. 

Let me know what you come up with. BTW, maybe even getting rid of the ferrites will help if they somehow were sucking too much influence on 40M.. but just a wild chance on that.

T

OK Amers
Tom what number bulb can be used to fine tune balance??

Here is a little recap I sent to Tim.
Hi Tim,
I bought 50 feet of 1/8 inch copper from Lowes.I wound 39 turns on a 4 inch OD PVC. For my antenna system, I am using about 4 turns INTO the coil for my first capacitor tap for 160M. The input coil is on a ceramic form, maybe  3 inches and 6 turns there.
I removed the beads and just have RG213 coming to a PL259 to interface to my transmission system. It slightly changed 40M settings, but I'm happy.
The hassle is that I have to leave the shack and walk 25 feet to the tuner if I want to change freq.
The proof will be throwing AM power to it and gathering signal reports.
I haven't found time to look in the MFJ manual for the Xs and Rs readout. I know that when I see a perfect 50 ohm match 1:1 SWR that the Xs = 0. So, I always try to play with taps and move the input coil slightly to get the Xs lower. My three bands are all siingle digit Xs and very near 50 ohms.

Fred

So, you're moving the input coil a little to get a better match? That's interesting - never heard anyone doing that. But, it will certainly have an effect, just like a link coupled final.  Whatever works but maintains balance is OK.

For the bulbs, any flashlight bulb will do. Solder 2" leads to each one and take one bulb and bridge it onto ONE feeder. Spread the connections, maybe 2" apart. Farther apart for a brighter bulb at a given power level. Be careful not to blow it out... start with QRP and ramp up.  You want the bulb to BARELY glow. Just get the filament to glow slightly.  Do this for the two bulbs. Put them at the same distance down the line.  Look at them together and compare brightness.

Tap OUT one feeder one turn to make the dimmer bulb brighter or vice versa.

Make sure the tuner is sitting at least 6" above any metal tables, etc, or you may be introducing an inbalance. Remember that the components are floating, just like the feedline. The only thing unbalanced is the 50 ohm coax coming in... and it is link coupled into the balanced tuner, thus no problems.

73,
T

#48 or #49 bulbs are the most sensitive, if you wanna use lower power - 2V@60 mA.

I have to say, I am confused as to how to wire the bulbs for the balance indicator.  I understand you start at low power and increase until it is a useful low brightness for comparison.  But...

Are they in series or parallel with each leg of the feedline?

And if they are in parallel, where does the other lead of the bulb go (to ground?)?

There is no direct connection to the feedline.
Solder 4 or 5 inches of insulated solid #24 wire to the bases of the bulbs. Has to be a quick tack solder.
Then wrap the wire around the feedline. You are going to induce the RF voltage on the feedline into the wire and that voltage will light the bulbs.
Hope this helped

fred

Fred,

That's an interesting way to do it, OM. I never thought of that type of RF coupling to light the bulbs.  It will work FB.


David,

The other way is to take two 6V bulbs and solder leads to them. Then take one bulb and spread the leads about 3" apart and solder them to ONE feeder. ie, one bulb on one feeder leg. The distance apart will determine the RF pickup from this single feeder wire.  Then do the same thing for the other leg.

By varying the wire distance you will vary the bulb intensity. As little as one inch or as much as 6" will work depending on if this is a voltage or current point, the resistance of the bulb and the power you run.

Just to be clear... the bulbs do NOT go across the two feeders... each one spreads itself out on one feeder and simply senses the voltage drop (IR) drop on one wire at a time.  Set the bulbs up so that they barely lite to give your eye the maximum sensitivity for balance measurements.

OK now?

T

Ah, I get it now.  Your suggestion implies open wire feedline.  Or at least stripped ladder line.

I was thinking insulated ladder line.  For this I see how Fred's RF induction would be better, but I am not sure what the other leg of his bulb is connected to, or is it the same deal for his, except both ends of the bulb are induced, and not direct connected?

David,

Yes, I believe Fred's idea  means a single wire across the bulb connections with the other end as a closed loop and wrapped around the single feeder wire. Picture the lead like the secondary of a transformer and the bulb is the load. (And the feeder wire as the primary)

That would be a better technique for insulated feeder wire...

T

Boy, do I feel stupid for how long this took me.

Does anyone have a good source of affordable (what do you consider affordable?) 500pF @ 5kV breadslicer air variable caps?

This is all I can think of:

• Hamfests ($(deals can be found))
• eBay ($(sky high))
• TenTec ($69, UK site (http://www.aoruk.com/tentec/kits/1207/1207.htm) has specs that the US site (http://radio.tentec.com/kits/Accessory) does not have)
• Palstar ($110, (http://www.palstar.com/c600.php))

Hello from MOP radio,
I have had good deals buying vacuum variables from E-Pay. Believe it or not!

Fred

Well, I have procured a sizable varfiable cap from ebay at a reasonable price.  But now that I have received it I see there is notable white corrosion on the plates (both rotor and stator).  Is this likely aluminum oxide or perhaps something else?  Is there some way I can clean it without removing all of the plates?  Or should I just leave it alone?

Steve THE HUZMAN,
Gave me some advice to clean a bread slicer..........cook in tomatoe sauce for a few hours and it will look like new!!!!
You will have to lube the pivot points and give it a thorough drying.
Has anybody tried this???
It worked for me.

Fred

Just drop it in a pot of bubbling tomato sauce?

yeas   As We all know, sause is reactive to most metals, thats why we only cook the sause in Stainless Steel or Cast Iron Heavy Duty pots... it will clean the breadslicers.... dont eat the sause.......    this is another reason to use oxygen free materials in electronics



KLC


"Thats a spicy meatballa."

Shaft Reducer Question:

OK, it turns out that my breadslicer cap has a 3/8" shaft.  I was wondering, does anyone know where I can find a 3/8' to 1/4"  shaft coupling without paying $65 for one at Nebraska Surplus?  Or perhaps someone has made some themselves.  I will probably head to the hardware store today to search for some homebrew inspiration (plastic compressiono fittings perhaps?).


Insulating Standoffs Question:

Can I forego these things (homemade or prefab) if I make this thing on 3/4" plywood or plexiglass?  Pllexiglass seems pretty inert, but plywood seems to have all that glue in it for potential conducting paths at kV levels.  Or am I over-thinking in my concern?

Hi Dave,
I cringe, like you, when I think of Surplus Sales...............but they always seem to have what we need. Someone over there had an outlook for the future. The stuff I have purchased from them is almost always new and wrapped up in military type packing.
Did you try Fair Radio?
Fred