HW-100 Alignment

[VA3WPN]

So Iv been reading, and a lot of what I read tells me that the manuals are incorrect A LOT of the time. Can anyone shed some light on this for me? I was following the book, and it wasnt very clear to me what I was needing to look for.

For instance :

Adjusting the Bias till the needle points to the triangle. Well... it whent there once, but after I lost my place and whent back.. It wont even go close. It seems to max out!

I started over again fresh from new, and the same results.

There was some blue arcing going on in the adjustable cap for the final tuning. but nothing burnt.

[K9TW]

There is nothing wrong with manual regarding setting the 6146 final tubes resting plate current. Any time you are trying to set final tube resting plate current by adjusting the bias voltage pot and the plate current meter pegs FSD (full scale deflection) you need to immediately un-key the rig. In fact you may not be quick enough to avoid damaging the finals. The finals have run away with no bias voltage on control grids.

When you are adjusting the bias pot with rig keyed in SSB mode and Mic gain turned down you are setting the negative bias voltage on Pin 5 control grids of the final tubes to approx -60 vdc. At -60 vdc you should see the plate current (actually cathode current) at the Triangle which is approx 50ma.

Again if the resting plate current jumps around or pegs the meter stop immediately. It only takes a moment for the 6146 finals plates to glow red and the tubes damaged. I suspect that is where you are at now.

Here is what I would do.
1. Let HV caps discharge, measure B+ at top of plate choke in PA cage, remove both final tubes. Make sure anode caps are in the clear
2. Connect multimeter to 6146 tube socket Pin 5 and key rig in SSB mode with mic gain down
3. Adjust bias pot for -60 volts at Pin 5
4. If bias voltage is not steady unkey the rig
5. Turn off power and spray clean bias pot with favorite contact cleaner and run wiper thru its range several times. Blow out bias pot with canned air.
6. Repeat bias voltage set test to make sure you can obtain a steady -60vdc at Pin 5
7. If you can, then install spare set of 6146 tubes and attempt to set resting plate current to the Triangle. Again if current is jumping around or pegs at any time QUIT and come back for more help.

As for blue arcing at Plate Tuning capacitor hopefully you have not arced across the plates and caused pitting and raising of metal on the plates. I would do a good visual inspection and run air variable thru its range and make sure no rubbing. Normally it takes a lot to develop short between the plates of the Plate tuning cap (tank cap) . The Loading capacitor has closer plate spacing and easier to arc over.

One last thing make sure while you are setting resting plate current and performing any transmitter alignment/testing that you have rig on 50 dummy load. Terry k9TW

[W5RKL]

So Iv been reading, and a lot of what I read tells me that the manuals are incorrect A LOT of the time. Can anyone shed some light on this for me? I was following the book, and it wasnt very clear to me what I was needing to look for.

For instance :

Adjusting the Bias till the needle points to the triangle. Well... it whent there once, but after I lost my place and whent back.. It wont even go close. It seems to max out!

I started over again fresh from new, and the same results.

There was some blue arcing going on in the adjustable cap for the final tuning. but nothing burnt.

Providing there are no other problems with the HW-100 and the final tubes, as Glen stated, have not been damaged, it is quite possible the HW-100 HET OSC coils have been
adjusted wrong. The manual states to adjust the coils on the "slow peak" side. I have worked on a number of HW-101 that owners adjusted the coils wrong, adjusted for a
peak on the "rapid peak" side of the adjustment. If the coils are adjusted for a peak on the "rapid peak" side of the adjustment, the symptoms you are experiencing will occur.
I've also had the same symptoms occur in the SB-400 and SB-401 transmitters as well as the SB-100 - SB-102 series transceivers. Try readjusting the coils as outlined in the
manual's alignment section, using the "slow peak" side of the adjustment.

73s
Mike

[K9TW]

Hi Mike: I am confused. I read that he was attempting to set resting plate current. Had it for a moment and then plate meter pegged and he saw an arc. He shouldnt have any drive while adjusting resting plate current. What am I missing? Maybe I read the problem statement wrong? Would not be the first time!

I wonder if the arcing he saw from PA cage was inside tube envelope and not at tank capacitor? Might also want to look at plate blocking/coupling capacitor. If it is bad it could place anode voltage across the tank cap. I dont recall the HW-100 having a protective choke on rf output to blow fuse? Terry K9TW

[W5RKL]

Glen,

I read the arc statement to. He said

There was some blue arcing going on in the adjustable cap for the final tuning. but nothing burnt.

Typically arcing occurs in the LOAD capacitor, not the PLATE capacitor. Arcing in the LOAD capacitor can result from using the wrong rubber "O" ring, too small diameter. This
put undue upward strain on the capacitor bearings causing the shaft to shift, shorting the fixed and variable plates. I've run into this from time to time but in most cases the
plate short when the LOAD capacitor is rotated to a certain point. He can check the capacitor by removing power, remove the top cover and the cover from the final amplifier,
remove both tubes, set the LOAD tab fully CCW, then connect an "analog" ohm meter across the fixed and variable plates of the LOAD capacitor. If the plates of one or all
3 sections are shorted the ohm meter will display zero ohms. No short the ohm meter will show infinity. Slowly rotate the LOAD tab CW while watching the ohm meter. Again,
if the plates short then the meter will show zero ohms. Fixing this problem can take a lot of work. I've fixed shorted LOAD cap plates before without removing the cap but it's
not easy.

No the HW-100, like the HW-101, does not have a protective RF choke across the output to ground.

My response was to give him another area to look at. I should have prefaced my response to indicate that, my mistake.

I agree, the arc could be in the base of the 6146 tube(s). He didn't indicate whether the fuse or breaker in the power supply blew/tripped which it would if the arcing occurred in the tubes.
Arcing in the tube(s) will result in a bright light and a loud arcing sound. The level of current flowing in the tubes will easily exceed the rating of the PS 4 amp fuse/breaker. He didn't say
whether the fuse or breaker blew/tripped.

Arcing in the LOAD capacitor typically doesn't cause the fuse/breaker to blow/trip if the transmitter is shut down quickly when the arcing in the LOAD capacitor occurs. Also, arcing in the
LOAD capacitor quite often, not always, occurs at a certain setting of the LOAD capacitor. The sound of arcing in the LOAD capacitor is different than the arc sound in the base of the
tubes.

If the arc is found to be in the base of the 6146 tubes then replace both tubes with 6146As. The arc in the base is more than likely caused by excessive gas and running the tubes on filament
voltage only, in receive (tubes are biased to cut off), will not eliminate the gas. Replace both tubes and test.

73s
Mike

[VA3WPN]

Wow this is a TON of info, and I thank you all for it. Im very very new to this, and Im working with a really really beat up manual. some if not most of the pull out diagrams are missing, so sometimes its a crap shoot for me. Im looking into getting a better manual, or finding a digital one that has ALL of the information. Not just parts of it, its no better then the beat up one I have

So today I tried to go threw it again, same result. The lowest I could get the needle to come down was at the S9 mark on the meter. So It struck me... Maybe the input voltage is too high. SO I switched the power supply over the LV250, and I could adjust the bias No problem. Now I have to go threw all of the voltage checks to find the problem. Wich is going to take a weekend for me to do. So, this radio is starting to be a big hassle. but.. its a good learning experience. I believe that if its broken, you can fix it. And I intend on doing just that. Even though I REALLY have no idea what Im doing, and Am Just following the instructions.

[VA3WPN]

And, No, it wasnt popping the breaker on the Power supply either.

[W5RKL]

Wow this is a TON of info, and I thank you all for it. Im very very new to this, and Im working with a really really beat up manual. some if not most of the pull out diagrams are missing, so sometimes its a crap shoot for me. Im looking into getting a better manual, or finding a digital one that has ALL of the information. Not just parts of it, its no better then the beat up one I have

So today I tried to go threw it again, same result. The lowest I could get the needle to come down was at the S9 mark on the meter. So It struck me... Maybe the input voltage is too high. SO I switched the power supply over the LV250, and I could adjust the bias No problem. Now I have to go threw all of the voltage checks to find the problem. Wich is going to take a weekend for me to do. So, this radio is starting to be a big hassle. but.. its a good learning experience. I believe that if its broken, you can fix it. And I intend on doing just that. Even though I REALLY have no idea what Im doing, and Am Just following the instructions.

The "LV250" voltage setting should not be used with the HW-100. The LV250 is for the mono banders, HW-12, HW-22, and HW-32. The HP-23 LV supply setting should be set
for LV output of 350VDC when used with the HW-100. I doubt your problem is caused by the HP-23 PS LV setting/wiring. Verify the bias supply is providing the correct bias voltage. You can
measure the bias voltage at pin 1 on the PS 11 pin connector. The voltage should be -101VDC or so.

Have you swapped the final tubes with known good tubes? If not, I would do that first.

As Glen stated in an earlier response, measure the final tube grid voltage at the grid pins on the final tube sockets, pin 5. The "negative" voltage at pin 5 of the final tubes should be
a negative voltage of approximately -95VDC to -100VDC in receive, changing to a negative voltage of approx -65VDC in transmit.

Fixing the full scale PLATE current indication should be fixed first then move on to the arcing problem, i.e., concentrate on one problem at a time.

You can purchase a complete assembly manual from

www.w7fg.com


73s
Mike
W5RKL

[K9STH]

RKL:

The Heath SB-110 and SB-110A also require that the low B+ be set for 250-volts and not 300-volts. In addition, the higher "low" voltage setting in all of the HP-23 series and the PS-23 is 300-volts and not 350-volts.

It really doesn't hurt anything to run the HW-100 and HW-101 from the 250-volt setting and not the 300-volt setting. However, the power output may be down slightly because of the lower screen voltage on the 6146 final amplifier tubes.

I would verify that, under load, the actual voltage when the power supply is in both the 250-volt and 300-volt settings. It is certainly possible, for some reason, the power supply voltages are higher than nominal and using the low voltage setting of 250-volts is closer to the normal 300-volts required by the unit. The 300-volt setting may be enough higher from 300-volts that the screen voltage is too high and, as such, there may not be enough bias voltage to properly set the resting current.

The screen voltage on the 6146 tubes should be checked. There is a possibility that this voltage is too high which, in turn, could cause problems with setting the resting current. Several things could cause the screen voltage to be too high including a couple of resistors.

Glen, K9STH

[VA3WPN]

Thanks guys,

I started going threw the initial testing

Where I tested for -300vdc I got -325vdc, and where I was suppose to get -110vdc I got -114vdc. ITs quite a large variation. But can the radio acount for this?