The AM Forum
March 29, 2024, 09:21:59 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   Help Calendar Links Staff List Gallery Login Register  
Pages: 1 [2] 3   Go Down
  Print  
Author Topic: K7DYY 80/40 Super Senior  (Read 33301 times)
0 Members and 1 Guest are viewing this topic.
WD5JKO
Member

Offline Offline

Posts: 1996


WD5JKO


« Reply #25 on: September 14, 2015, 09:31:15 PM »

    My take is that type acceptance, if required, just means I would not buy a transmitter so labeled. I am a builder, a tinkerer, and a modifier. If something does not work right, I try to understand it, and if possible fix it. Sometimes I go further and make it better than it ever was. If a rig is type accepted, wouldn't tampering with it affect the the type acceptance certification? This might even be illegal.

    At my work I repair commercial class E 13.56 mhz amplifiers. Once done, we keep a record of three pages of tests, and the unit is factory sealed. I don't understand why there are those in ham radio that want the same thing, i.e buy, plug in, hook up, talk...CQ CQ with no thought ever of what is inside that thing, or how does it work?.. I have resisted being an appliance operator all my adult life. That said, there is something in ham radio for almost everyone. But me, NO, I'll pass on that type acceptance, and the extra cost to purchase something so certified.

   Back to the thread, the K7DYY Super Senior is a pretty neat rig. Several people use them, and they love the things. They can be mated to an SDR receiver, or even and old Hammarlund Super Pro. Then add in the QIX modulation monitor, etc. to complete a station.

   Good Job Bruce!

Jim
Wd5JKO
Logged
W3RSW
Contributing
Member
*
Offline Offline

Posts: 3308


Rick & "Roosevelt"


« Reply #26 on: September 15, 2015, 08:38:52 AM »

"So the 40 meter version is shipping now?

I would think these things would be boring, great in every way but not much excitement?
No meters, no glowing tubes..."

********************************

But on the other end...  "OH, the audio."
  Tell 'em your using a Gates!
Logged

RICK  *W3RSW*
W3RSW
Contributing
Member
*
Offline Offline

Posts: 3308


Rick & "Roosevelt"


« Reply #27 on: September 30, 2015, 09:46:22 AM »

More thinking  (uh oh) on the dull no knobs or meters rig. 

Rack mount the DYY.
 In same attractive rack, mount your separate HB tuner with a lighted watt meter, another lighted SWR meter and a couple of lamps for various switch positions along with at least two tune and load knobs plus a band switch knob. Might even want lighted indices for same.

Also install another matching AC power input panel with exotic big boy switches,maybe even a twin breaker, separate aux. AC jacks, etc. along with a big sassy AC line voltage meter ( you do check your sag, don'cha )
Don't forget to add the essential Ip or I'd equivalent meter in the AC box, a big lighted AC wattmeter / power meter to show quiescent vs. quasi peak power differentials when modulated.

Now add another matching panel or two in the same rack for all your audio gear, starring of course the biggest, strappinest lighted VU meter you can find. Don't forget at least 10 knobs, another twenty sliders, and numerous switches with indicator lights.

All above for the retro man. If you go modern, wanna be the LED King, then sky's the limit.
 Grin

Oh and almost forgot the best. Another panel or rig top flasher modestly behind perf. shielding showing fluorescent blue modulation swing alom with with warm yellowish background glow to simulate those always-on pubes.
You know, trick it out like 27.185 brethren.
Logged

RICK  *W3RSW*
flintstone mop
Contributing
Member
*
Offline Offline

Posts: 5055


« Reply #28 on: September 30, 2015, 06:21:16 PM »

I  guess the present cost of the Super Senior, negates any fancy meters and whistles and bells.
Now exploding RF devices might be a little extra.
I hope Bruce can figure out what is going on and maybe beef them up a little, instead of running them close to design parameters.
I enjoyed the little Class D 80M transmitter. 125watts in the palm of your hand. It needed the isolation transformer, though.

Logged

Fred KC4MOP
WB5IRI
Contributing
Member
*
Offline Offline

Posts: 117


« Reply #29 on: October 05, 2015, 11:51:32 AM »

Got the transmitter back last Thursday, while I was out of town. Hope to get it back on the air tonight. I'll let everyone know how I fare.
Really fast diagnostic from Bruce, and good communication. He burned it in over a couple of days, so everything should be good. In any manufacturing process things are bound to happen. A cracked FET case was the issue, and it was found, fixed, tested, and returned in record time and with professional, hassle-free courtesy.  Don't see how anyone could improve on that.

Doug
Logged
W3GMS
Contributing
Member
*
Offline Offline

Posts: 3063



« Reply #30 on: October 05, 2015, 03:18:57 PM »

Got the transmitter back last Thursday, while I was out of town. Hope to get it back on the air tonight. I'll let everyone know how I fare.
Really fast diagnostic from Bruce, and good communication. He burned it in over a couple of days, so everything should be good. In any manufacturing process things are bound to happen. A cracked FET case was the issue, and it was found, fixed, tested, and returned in record time and with professional, hassle-free courtesy.  Don't see how anyone could improve on that.

Doug

Best of luck with it Doug and hope it works out this time.  I do believe that Janis-AB2RA is still happy with her 80-40 DYY rig.   It sure sounds good on the air. 

Would appreciate hearing your feedback after you have been operating it awhile.

Joe
Logged

Simplicity is the Elegance of Design---W3GMS
WB5IRI
Contributing
Member
*
Offline Offline

Posts: 117


« Reply #31 on: October 12, 2015, 12:15:07 AM »

Been using it quite a bit, and it seems to be working FB. Good reports on the audio. Can't seem to get to 100%modulation at 375 watts, but that might be due to my audio preamp set up. Can get easily to 110% positive peaks at 315 watts carrier, does not exceed 100% negative peaks no matter what I do. I think I'm gonna like this little transmitter. Stays cold to the touch even after a buzzardly transmission.
Doug
Logged
w1vtp
Member

Offline Offline

Posts: 2638



« Reply #32 on: October 12, 2015, 09:39:45 AM »

Been using it quite a bit, and it seems to be working FB. Good reports on the audio. Can't seem to get to 100%modulation at 375 watts, but that might be due to my audio preamp set up. Can get easily to 110% positive peaks at 315 watts carrier, does not exceed 100% negative peaks no matter what I do. I think I'm gonna like this little transmitter. Stays cold to the touch even after a buzzardly transmission.
Doug

Is your microphone in the proper phase? Or maybe there is a stage in your AF chain that is clipping on the hi peaks.

Al
Logged
w1vtp
Member

Offline Offline

Posts: 2638



« Reply #33 on: October 12, 2015, 09:49:55 AM »

Some of the successful users of the DYY xmtr have had to dial the carrier back to 200 - 250 watts to get that positive peak.  It may be you are hitting the 1500 PEP limit at 315 watts.  Try lower carrier levels and see if those positive peaks on the REA monitor start showing up

Al

PS: I did some calculations assuming the normal asymmetry of the male voice of 150% positive peaks, assuming proper mic phasing.  You might try running the carrier at 240 watts   You may be hitting the rig with as much as 1970 watts PEP which may be flat topping and perhaps stressing the output mosfets


PPS:  That may be why Bruce is recommending a phase rotator which would remove this asymmetry issue altogether and allow you to run 375 watts carrier is that's your "bag."


* DYY XMTR - 150 PERCENT WITH 240 WATTS CARRIER.jpg (53.7 KB, 610x184 - viewed 434 times.)

* DYY XMTR - 150 PERCENT WITH 315 CARRIER.jpg (89.65 KB, 707x362 - viewed 400 times.)
Logged
WB5IRI
Contributing
Member
*
Offline Offline

Posts: 117


« Reply #34 on: October 12, 2015, 10:43:13 AM »

Thanks, Al.
Very interesting. Audio is not my specialty, RF is. I blush to admit I have never even heard of a phase rotator. I will do some research, and I'll dial back the carrier to 250 watts tonight and see what happens into my dummy load. My mic preamp does have a phase shift button, but it seems to have no effect with the DYY rig -- everything is the same no matter which position the switch is in, according to the REA modulation monitor. It does make a considerable difference with my Multi-Elmac AF68, though -- one position is very much louder and has less background pickup than the other.
Yes, at 375 watts, driving it over about 80% modulation results in visible flat topping on the modulation monitor. Nothing in the instruction sheet about that, so dialing this transmitter in is a learning process.
Don't really have a thing about needing to run 375 watts, just putting the transmitter through its paces to see what it will do. I've just joined the DYY reflector, so I will look for posts there about the audio characteristics.
Doug
Logged
w1vtp
Member

Offline Offline

Posts: 2638



« Reply #35 on: October 12, 2015, 02:36:52 PM »

Doug

Just remember that it's all about that 1500 PEP spec.  The problem with using a scope to monitor the PEP is that you need to be able to supply a 1500 watt CW source to calibrate the scope.  After that, you have to deal with the persistence of the scope to show all those tiny transient peaks that are hard to see.  The REA monitor is the best approach along with the ability to do the math to know where you hit the 1500 PEP value given the carrier power and an accurate way to measure the % modulation.

Exceed the 1500 watt PEP spec and you are asking for flattopping or worse splatter / failure.  The DYY can have a failure problem.  We still do not have a common failure that can be isolated.  It seems like there is a component quality issue with that rig from time to time.  We've discussed designing too close to maximum components used in the transmitter on this forum but Bruce also has to deal with a price point that is acceptable with the amateur radio community.

Gl to you Doug  and Bruce, Gl as you continue to keep this neat transmitter available to us.

PS: Bruce points to an article discussing the merits of phase rotation. 

http://www.w3am.com/8poleapf.html
Logged
nq5t
Contributing
Member
*
Offline Offline

Posts: 557



« Reply #36 on: October 12, 2015, 04:51:14 PM »

I have decided to eschew the whole messy audio chain thing with mine, in the interest of less stuff is better.  I have the new version of the D-104 processor with the phase rotator and a shiny D-104 to put it in.  

If I can sell my house, get moved, and get an antenna up in a new place, I'll have my 80/40 back on at some point in the next few months.

While I had the 80/40 on the air, I ran it at about 300 watts carrier.  For no particular reason other than there's no point in pushing it.  100% modulation (on the REA) with no signs of flat topping.  I did have a phase rotator in line, and didn't really experiment with how the SS behaves with asymmetrical audio.

The SS will do 375 watts carrier 100% modulated.  So if you run it at the limit and try to modulate over 100% on peaks you can expect it to flat top.  I suppose the same would be true if you ran it below 375 watts, and tried to modulate with 100++% that attempts to push it beyond the limits of the transmitter.

Grant NQ5T
Double Oak, TX on the way to Savannah, GA
Logged
flintstone mop
Contributing
Member
*
Offline Offline

Posts: 5055


« Reply #37 on: October 12, 2015, 06:01:39 PM »

Thanks, Al.
Very interesting. Audio is not my specialty, RF is. I blush to admit I have never even heard of a phase rotator. I will do some research, and I'll dial back the carrier to 250 watts tonight and see what happens into my dummy load. My mic preamp does have a phase shift button, but it seems to have no effect with the DYY rig -- everything is the same no matter which position the switch is in, according to the REA modulation monitor. It does make a considerable difference with my Multi-Elmac AF68, though -- one position is very much louder and has less background pickup than the other.
Yes, at 375 watts, driving it over about 80% modulation results in visible flat topping on the modulation monitor. Nothing in the instruction sheet about that, so dialing this transmitter in is a learning process.
Don't really have a thing about needing to run 375 watts, just putting the transmitter through its paces to see what it will do. I've just joined the DYY reflector, so I will look for posts there about the audio characteristics.
Doug

I understand that you are using the REA monitor to see your positive peaks. I am using the REA monitor too but I still prefer to look at the carrier through a little RF sampler and the good 'ole scope.
I think the TX might not like slammin' the negative peaks if you are seeing excessive white baselining in real time using a 'scope
Fred
Logged

Fred KC4MOP
WB5IRI
Contributing
Member
*
Offline Offline

Posts: 117


« Reply #38 on: November 13, 2015, 12:06:11 PM »

Just an update on the Super Senior. It's working FB now, and it has become my go-to transmitter on 75 and 40. I have installed the K7DYY audio board in the base of one of my Astatic mic stands, and I have tried it with several different heads -- JT-30, 77, D-104, DR-10 Crystal, DR-10 Dynamic, and a couple of others (you may have gathered that I collect vintage Astatic mics). Nice to be able to just switch heads and do A/B comparisons. On-air reports indicate the 77 and the DR-10 Crystal sound the best, with the DR-10 coming out on top. Full, rich audio, and it has a switch on the back that shifts the curves from low emphasis to high emphasis (Astatic calls it the "crisp" setting) that works really well for times when the bands are noisy and I need more punch on the high end.

The DR-10/K7DYY board combo replaces an ART TPS II tube preamp, 31-band EQ, and dbx266xs gate/compressor. Reports are that it's smoother than the audio chain setup, which probably means I have too much compression dialed into the dbx, but what the hey, it's a simpler set up and takes up no space, so I think that's what I'll go with in the future. I do occasionally still trip the safety on over modulation -- it's the most sensitive I've ever used -- but very rarely now.

Happy camper. Someone comes out with a rig like this at the power level this one has for all the hf bands, and I will buy it.

Doug
Logged
W3GMS
Contributing
Member
*
Offline Offline

Posts: 3063



« Reply #39 on: November 13, 2015, 04:04:55 PM »

Thanks for the report Doug.   Its appearing to play well for you and that's great!   

I believe that rig is rated for 375 carrier output.  Have you confirmed that and if so under what positive modulation percentage are you able to achieve. 

I believe the new pre-amp board for the D-104 uses a phase rotatory to make the human voice audio symmetrical.  If so, that should reduce stress by limiting the positive voltage during positive peak modulation on most voices which are non symmetrical.       

73,
Joe-GMS 
Logged

Simplicity is the Elegance of Design---W3GMS
WB5IRI
Contributing
Member
*
Offline Offline

Posts: 117


« Reply #40 on: November 13, 2015, 05:05:07 PM »

It will do 375 watts, in fact, it will do more, although Bruce warns against trying that. FETs are pretty unforgiving, so pushing things beyond the limit is not wise. Moving from 80 to 40 meters requires a readjustment of the carrier level. The setting that gives 325 watts carrier on 80 produces over 400 on 40. That's how I know it will put out more than 375! The carrier-adjust pot is a subminiature pot mounted on a circuit board and accessed through a TINY hole in the front panel using a miniature screwdriver. A knob brought out to the front panel would be more convenient, but I guess you can't have everything. Thinking about how I can mount some type of adjustment external to the front panel, but not there yet.
I cannot seem to get 100% modulation at 375 watts carrier. I can get it at 340, though, and I usually run the transmitter at around 325. As the rig is used a bit (it never feels even warm to the touch, just not ice cold after some use -- I don't call that warm), the power output tends to rise slightly, so why stress things, and the difference between 325-340 watts and 375 is not even noticeable on an S meter. I may ask Bruce why I can't seem to get 100% modulation at full power output one day, but for now I am having too much fun.

I am using a Bird 43 watt meter and REA modulation monitor.

Doug
Logged
w1vtp
Member

Offline Offline

Posts: 2638



« Reply #41 on: November 13, 2015, 05:13:04 PM »

I think for the DYY rig the phase rotator is an almost must.  This 375 watt carrier as a "spec" for legal AM operation is a myth.  I repeat my earlier comment "it's all about the 1500 watt PEP spec"  If you run the phase rotator then you will, hopefully, see symmetrical modulation.  That being the case then the relationship between 375 watts @ 100% modulation & 1500 PEP is intact.

On the scope.  I'd like to respectfully disagree with whoever posted their preference of the scope over the modulation monitor as there are some transient spikes that just will not be picked up by a scope but will be detected by the modulation monitor.  In any case, how is one going to calibrate the scope for 1,500 watts carrier using the K7DYY transmitter to calibrate the scope so that it will be accurate.  Just a friendly disagreement. I've included an attachment to show my calculations of the above mentioned mathematical relationship.

Regards, Al VTP


* 375 watt carrier with 100 percent mod.gif (19.5 KB, 710x497 - viewed 395 times.)
Logged
N2DTS
Contributing
Member
*
Offline Offline

Posts: 2307


« Reply #42 on: November 13, 2015, 06:16:20 PM »

In my case, I care mostly about over modulation in the negative direction and a scope shows that for sure, at all power levels and there is no calibration needed.
My scope sits on the iF outputs of the home brew receivers, and it tracks with the mod monitor on positive and negative, I adjust it to 4 divisions (or 40, depending on how you count, and when the carrier gets closed down its VERY easy to see.
When I hit 8 divisions its 100% positive or close enough.

This is a sine wave, but works the same with voice:


My mod monitor seems to be 5% off, it was showing 95% at this point...
Logged
WA5VGO
Member

Offline Offline

Posts: 158


« Reply #43 on: November 13, 2015, 06:30:41 PM »

A good friend of mine bought one about 3 weeks ago. It let go last weekend. I think he's going to return it for a refund.

Darrell
Logged
w1vtp
Member

Offline Offline

Posts: 2638



« Reply #44 on: November 13, 2015, 07:18:41 PM »

A good friend of mine bought one about 3 weeks ago. It let go last weekend. I think he's going to return it for a refund.

Darrell

I hope he will rethink things and just ask for it to be repaired

Al
Logged
Jim, W5JO
Member

Offline Offline

Posts: 2506


« Reply #45 on: November 13, 2015, 07:43:48 PM »

Some of the successful users of the DYY xmtr have had to dial the carrier back to 200 - 250 watts to get that positive peak.  It may be you are hitting the 1500 PEP limit at 315 watts.  Try lower carrier levels and see if those positive peaks on the REA monitor start showing up

Al

PS: I did some calculations assuming the normal asymmetry of the male voice of 150% positive peaks, assuming proper mic phasing.  You might try running the carrier at 240 watts   You may be hitting the rig with as much as 1970 watts PEP which may be flat topping and perhaps stressing the output mosfets


PPS:  That may be why Bruce is recommending a phase rotator which would remove this asymmetry issue altogether and allow you to run 375 watts carrier is that's your "bag."


From the K7DYY site:

 160m/80m * 80m/40m
The SuperSenior covers two of your favorite bands. It is available in TWO models, one covering 160 and 80 meters and the other covering 80 and 40 meters.


Legal Limit
The SuperSenior provides LEGAL LIMIT output with up to 375 watts of carrier (adjustable from front panel) and audio peaks reaching 1500 watts, no time limit!



So what is the deal with these things, if speced as above why won't it do it without breaking?
Logged
N2DTS
Contributing
Member
*
Offline Offline

Posts: 2307


« Reply #46 on: November 13, 2015, 09:16:41 PM »

Why not just run the thing at 300 watts carrier?
No one can tell about the extra 75 watts of carrier at the far end.
Logged
WD5JKO
Member

Offline Offline

Posts: 1996


WD5JKO


« Reply #47 on: November 13, 2015, 11:34:35 PM »

I have tried it with several different heads -- JT-30, 77, D-104, DR-10 Crystal, DR-10 Dynamic, and a couple of others (you may have gathered that I collect vintage Astatic mics). Nice to be able to just switch heads and do A/B comparisons.

    Doug,

   Glad your having fun. I suggest you scrutinize that preamp output with a scope, especially as you try different Mic elements. I own 2nd generation K7DYY pream pcb. This one had one pot, and no phase rotator. My two MC-320 elements would both overdrive the processor if spoken closely into the screen. I had to cut back the drive to the processor, and then as a result I needed to adjust the noise gate so it did not chop up my speech. I made it pretty decent, but it still would clip during the processor attack time. I ended up with a post processor clipper that only clipped when the processor output had a big spike during the attack time.

   I wonder if these processors when overdriven are part of why some of the Super Seniors go through a melt down?

The picture attached was the stock preamp with a close talked "SSSSSSSSSSSSS". I was able to correct that as described, but the brief spikes during the attack times remain.

Jim
Wd5JKO



* D104_3.jpg (64.74 KB, 1024x768 - viewed 402 times.)
Logged
WB5IRI
Contributing
Member
*
Offline Offline

Posts: 117


« Reply #48 on: November 14, 2015, 10:21:29 AM »

Now, that is interesting. My board is the latest one with the phase rotator. Peaks look symmetrical on the mod monitor. Haven't looked at it on a scope yet, but will.

The only adjustment is the output. I would like to be able to adjust the noise gate a bit, though. It takes a couple of seconds to settle down when first keyed, then works fine, eliminating all background noise. Faster attack time would be good so there is no blast of fan noise on key-up until the gate kicks in.

But these are quibbles. The rig is not perfect, but it darn sure is very good at what it does. First comment I always get when I make a new contact is " you sure are loud," followed by "outstanding audio." 

My Super Senior failed right after I got it as well. Sent it back, and Bruce repaired it and burned it in for a couple of days before returning it to me. Been working FB ever since.

Doug
Logged
W1DAN
Contributing
Member
*
Offline Offline

Posts: 899



« Reply #49 on: November 15, 2015, 07:22:20 PM »

Folks:

The K7DYY Super Senior (160m/80m model) at the W1ZZZ palace can create a 240 watt carrier under full +125% dense modulation (using external broadcast processing). As the carrier is brought up, the positive modulation is clipped earlier. We have never been able to 100% modulate a 375 watt carrier.  In the end, this is not much of an S-meter difference.

Bruce works aggressively to resolve technical issues and has repaired Peter's transmitter multiple times at no charge.

73,
Dan
W1DAN
Logged
Pages: 1 [2] 3   Go Up
  Print  
 
Jump to:  

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
 AMfone © 2001-2015
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Page created in 0.07 seconds with 18 queries.