I just started on restoring a Lafayette HA 63a. I know it is a cheap and problally worthless. But it needs my help. LOL On first inspection I noticed someone has removed the position of the audio tube away from the the transformer and moved it to a place behind the front dial. Why? All the wires are jumpered to the new socket. The diodes have been replaced with two silocone ones, but I dont see a resistor in line to lower the voltage any. Maybe this is ok I would have guessed to keep all votage the same you have needed one to drop some voltage on the tubes. Also for some reason the manual has been written in describing how the new alignment processs is done with the bandspread set on 60 and not 100. I have brought it up slowly and nothing blew and no sound as well. I am guessing one tube or section is not working at all. Any ideas on the movement of the tube. I just cant believe it got that hot or harmonics from the transformer causing trouble. Thanks

I'd put it back the way it was. There is no good reason to eliminate the rectifier tube. Whatever benefits he thought he was getting were lost by the increased B+ voltage and added stress on the power transformer.

Audio tube makes no sense. I believe it was mounted near the rear apron, which was
probably the best place for it. Sounds like a real hack got into that radio and did a lot
of silly changes for no sound reasons.

Regarding the band spread, I'd bet he did that so he could use the control for tuning
either of station as the receiver drifted. I keep my band spread dial off a tad on my
HE-30 just for that reason. Silly radio drifts even on the AM band, LOL!

Pete

If you align the set with the bandspread control set at 60 rather than 100, it can be used as a fine-tuning control allowing you to go above and below the desired frequency. It makes more sense to use this type of uncalibrated bandspread dial in this manner.

I agree with Pete. This isn't the most stable of boatanchor wannabees.

Dave

Well as I continue to go through this radio tonight, I have come across another weird something I still dont understand. There is a 10 ohm resistor across the output leads of the audio transformer. For the life of me I cannot figure this one out. This one still stumps me. I found this same mod on another site showing it for a future repair. I just dont see the reason for lowering the impedance on the output unless there was a problem on the transformer.
Another problem tonight I just discovered was that some tubes have no hearter voltage, which tells me the power supply mod was not done correctly. Also on the last voltage check before I quit I got no voltage on the seconday for the heaters. Dont know if it is fuse blew, intermiten, or bad wiring which I have come acorss in several places tonight.
Radio is not worth the effort but in the long run it will be, considering it will be a learning curve and time well spent. No radio project I have ever undertaken was easy. I have made the decision to put it back as original. This will take some effort but I believe it will be worht it. If you cant fix em right dont get started, as an old ham use to say. He was right on this one. Poor skills and practices.
Thanks for your advice so far please keep in touch I could use your help along the way because I am not sure aoout some of my findings on other things tonight.

Curtis

I'm not sure what alignment instructions you're looking at, but the alignment instructions I have, say to set the Bandspread dial to 100.

The 10 ohm resistor across the audio output transformer; maybe previous owner was using a 4 ohm speaker and felt he needed it.

The power supply is solid-state; 1/2 wave rectifier (one diode). If there are two diodes now, it's probably converted to a full wave supply. All the DC voltages are probably out of spec. Most likely, all the tubes were running hot with excess B+.

Receiver sold for $60; our cost was around $23. But, it has 7 tubes, an AC transformer, RF stage, separate BFO stage, bandspread, and S-meter. Not a bad receiver for the price. We sold tons of them.

It's other claim to fame was that the cabinet was used for the prototype Lafayette HA-70 6 and 2 meter receiver designed by Trio.

Pete

Yes I agree Alan, you have it correct the power supply is solid state, but must have been selenium, could have been diode, dont know for sure because the schmatics only refer to a part number.
I stayed up after writting the last reply because I could not sleep thinking about it. Here is more of what I discovered.
The fuse holder fell apart in my hand. Just old I guess. From there I traced the power supply wiring. I do not believe it is a stock transformer. There are three sets of wires on the seconday. Two white, two striped green on white, and a set of orange or red one black striped. The orange/red and black stripe are used on the heaters. Only one set of the white and green stripped are used the other two are taped up. Tape. God I hate black tape.
Instead of one diode it has two, flows into the standard 40uF 300V caps. This is where it gets stange. From there we have a 300 ohm, then a 400 ohm, then a 390 ohm, and finally a 330 ohm all 10 watt resistors. All in series. I plan on disconnecting the transformer and measureing voltage to see what I have. After looking at the schematics in the book this is not the correct transformer. Is it possible to get a new one or make this one work? The transformer says RCA 970445-19, next line SUB 31, next line 450916. I dont know how to look up transfromers by numbers but maybe one of you fellows will know what I have.
I really dont know what to do now. I have found some resistors that need replacing and I will replace all caps other than the ceramic one to start with. I have a bunch of ceramics on hand. I still cant believe I am still up with this one this late. Thanks again
Curtis

Don't get discouraged. This is an excellent radio to learn with since, as Pete (manualman) said, it has a good tube lineup and the circuits are straightfoward. Are the two diodes in the power supply connected in series or in parallel? I think it would have been difficult to convert to full-wave without replacing the power transformer since the original doesn't have a center tap, as I recall. Those series of resistors may have been installed by the previous owner in order to get the correct value for the original. The 10 ohm resistor across the output transformer could have been installed to protect it when the speaker is disconnected and/or headphones are used. All of those plastic covered, aluminum cased caps (they are paper inside) will need to be replaced which are probably the major cause of the previous owner's problems.

I had one of these that I sold to a forum member some time ago. Seemed like it would be a decent set, once restored.

Dave

Well I am still up working and tinkering with this thing. Yes the diodes are set up just like a half wave supply. In the second set of schematics I down loaded it shows just one resistor and not the block with a Lafayette number. I am thinking that the bank of resistors were used as you stated to lower the voltage to a reasonable level for the tubes.
From all of my research on this set of tubes there is no reason for it not to be a nice set when finished. I had no luck looking for a transformer. I did not do an exhaustive search but I am sure someone on here will have the knowledge about where to go.

Sorry I ended my post by hitting the enter key.
I wanted to say that there are a few caps in there that have swollen tubes. I will replace all the caps now that said they were paper. I thought since they were in metal tubes they would pass.
One other circuit mod I have noticed is the addition of another large cap after the resistor mod. Sprague orange colored one. I will have to think about it for a while or look with a scope but I dont see the need for that one since the other two should cover the job, unless the original ones are bad and they did not want to got to more trouble removing them. Well I guess I have to figure out how to use this transformer or get a suitable replacement. I hope someone has the answers on another transformer.
Curtis

No may the original transformer could be changed to a fullwave using two diodes,
there is no center tap.

Are the two replacement diodes connected in series?

Make sure the transformer primary is set for 117 volts, and NOT on the 100 volt tap by
the last owner.

Halfwave rectifier into a 40uF input filter cap is rough on the transformer; I'd add a 47 ohm
resistor in series with those diodes to reduce transformer stress. Or I should ask, is there
an added resistor in series with the new diodes? I'm sure it was adequately
rated for the selenium, but a silicon diode changes things. If it were my set I'd go to a full wave bridge.

I have a KT-200 and a HE-30 that I use for general listening... fun to use even if they
are lacking in performance.

Pete

Just to clear up some possible confusion.....are you saying that both the Power and Output transformers have been replaced by a previous owner?

Dave

I'm getting confused too, but that is normal for me

Disregard my prior comments, since I don't know what was changed or what
is original at this point. Some photos might help, if you can post them.

Pete

Great idea I will post a pic just need to figure out how. Look for it tonight. There are no resistors before the diodes. There is a bank of resistors after the diodes, all in series. 400, 390, 330 and one other I believe. I will include a pic of that as well. Then the supply goes into a filter as on the schematics.

Here is the best I could do in a last minute Schematic.

Diode and resistor pics, also one of the resistors on the top just fell apart. I circled the two wires going to the top of the chassis and you can see the diodes to the left of the red wires, there not very good pics but it is useable.

Well after removing some wires and connecting across the transformer terminal, I get 350 volts on the diodes, and I get 1.6 volts on the heater voltages. So I guess I am in need of a new transformer. Can anyone direct me in the right direction. No sure if I should build a full wave bridge with a ct transformer or look around for another transformer with no ct. You guys have been at this the longest I need some advice. Thanks.

That is a real mess! Are you sure your schematic is right?? The transformer must
have a center tap on the high voltage winding for that rectifier to work.

It almost looks like someone replaced the transformer with one with a higher
voltage secondary than was used originally, and compensated for the high
B+ voltage by using a gaggle of power resistor to drop the voltage.
A lot power is being wasted as heat.

How are you measuring the filament voltages, do the tube filaments light? It seems
odd you have 350 volts B+ and that low a filament voltage without seeing smoke!
You should be measuring the B+ from the last filter cap to the chassis, what do
you see at that point to chassis?

If you need a transformer, I'd look for a cheap HA-63 and make one good
unit out of two.

Pete

Yes there was smoke of some sort. The large 400 resistor was cracked and has fallen apart, no shell on half of it and it started to smoke when I applied power. The filaments did light and the tubes were only warm to the touch not like a normal tube tempature. I took the transformer out and just measured voltage with no load. Not to far off other figures. I put transformer on variac and played with voltages on large 100 watt resistor and could never get voltage up on heater current. Its junk. I dont know where else to look, not sure about ebay. Now hear is another ineresting point. The BFO has been removed from operation. After the detector stage a rework of the audio has been done. Not sure why. The tube was remounted to another spot on the chassis. I started tonight placeing everything back to original. Some caps are bad some resistors are very low and high. I do have another question the caps that are in small brown squares with dots on them, are they Silver Mica, or just the old style of caps and need to go. I have not found one out of value yet. Most of them are on the IF cans and the front end tube. What should I replace them with? Thanks

I'm pretty sure that is a replacement transformer, and it looks like the
owner went to extreme measures to adapt a transformer that wasn't a good
fit to start with. Too much wasted heat energy; and the resistor wattage's
apparently were underrated as well.

A new transformer is going to set you back more than a less than
HA63 on eBay with cosmetic defects. Or, you could try an
ad in the classifieds if you know the original transformer's specs.
Regardless, I'd try to get it back to as close to original as practical.

Those sets are fun to play with... the KT-200 was my first receiver
as a Novice and although it was a poor choice, I still get a kick out
using it from time to time. The HE-30 is the same receiver, with
improved ham bandspread calibration and a Q multiplier that
was added on the old chassis.

Pete

Well I may have found a source for a transformer that is known to be good. I hope so. The new ones I looked at take the fun out of the whole matter. No matter what I have decided to do a complete restoration. I started soldering the correct parts to the proper places. undoing the audio mod. The whole cut out for the mod to remount the audio tube looks ugly but I think I can just clean it up an leave it. I may just cut out an aluminium disk and screw it over the mess. I guess I will do what looks best. Is it worth the effort to remove all the parts and clean the chassis or do some thing else? Thanks