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Author Topic: Heathkit TX-1 Apache, My Nightmare :)  (Read 13828 times)
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KC3GMQ
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« Reply #25 on: March 07, 2017, 04:39:05 PM »

Pete, 

*I have been using 40m on the crystal (7.295) when I try to load it, I have also tried the other bands just to see if it would load.  *I am using 40 because I have crystals for 40.  I am using xtal.  The vfo wasn't working right on 40. (it was working on all other bands until amp died)  A problem I had not addressed yet.  I was trying both CW and SSB also.
* Spotting button lets me adjust the Driver and Drive.  I get 6 ma easy on 40m.  I can here a small carrier type sound when using my Yeasu FT-920, but not what you would call a tone that I am used to hearing.
* I will double check the alignment of the switches.
* I will concentrate on CW only now.
* I have been using the light bulb in conjunction with a watt meter.  When in tune, i can get it semi bright, as soon as I go into transmit, it dies off and i get little or no dip on the plate.
*I am going to go thru clamp circuit again, also going to retest tubes, that is easy and I want to make sure they still read good.
*  I wanted and did pull the 6146 sockets only because I was using a web cam to video the insides while I was tuning, and there was some arcing under them when I reviewed the video.  Yes it is a pain to do that once the whole radio is put together, but I wanted to make sure nothing was burnt or contacting something else.  Not easy to see underneath.  Had to order some proper size hook up wire to replace another so It will be a few days until I get back to testing.  I will video my loading and post it on Youtube with a link here.  I am thinking it might give you and others a better idea of what is going on.  I thank you and all the others greatly,  I know how hard it is to help someone, especially with lite experience to try and fix something like this.  I can say however lol,  I am learning a lot quicker then I thought I was going to.

73
Dave
KC3GMQ
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Todd, KA1KAQ
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« Reply #26 on: March 08, 2017, 11:26:55 AM »

Dave, I haven't kept up well here so excuse me if I repeat something or make little sense. I'm like that more and more these days.  Grin

First, whenever I hear 'runaway' I think 'parasitic'. Maybe that's been dispelled already.

Second, it sounds like you may be right that the rig had problems from day one and was never right. WA2PJP who is a member here got a beautiful TX-1/RX-1 set a few years back that was like new because it was wrong from the start and got put in a closet somewhere, never used. He tore it down and rebuilt it like a new kit. I'd strongly suggest sending him a message here if he doesn't pop in at some point. He has a lot of experience debugging this transmitter and may be able to tell you right where to look. Or maybe not, but it's worth a try.

Lastly - hang in there, because once you're done, the Apache is pretty much a bullet-proof transmitter. Very stout iron, and with a few simple changes it can sound really good. The Mohawk is a far bigger PITA....

Good luck.
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K4RT
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« Reply #27 on: March 11, 2017, 02:52:11 PM »

Any one or more of the things that have been mentioned could be the problem(s).

If you haven't already found and corrected the problem, you may need to carefully check the build against the assembly section of thd Apache manual, focusing on the power supply & RF sections.  At minimum, I would check all PS sections and the RF chain from VFO & crystal oscillator forward through to the SO-239 on the rear panel. Before working underneath the chassis know how to safely check that the PS electrolytic capacitors have discharged.  I use a long-shank rubber handle screwdriver, and I check after every time I shut off the xmtr while working on it.  One hand behind your back is a good habit.

Take your time. Don't overlook band switches and related assemblies/linkages.  Following the steps in the manual will allow you to confirm that the transmitter was assembled to Heath's specifications, eg all components, leads, grounds, etc properly connected, and check the functionality of each component and stage.  Check off each step so nothing is missed.  This can be a challenge working in the layered assembly of some sections beneath the Apache chassis.  

I'm currently using this approach on a DX-100B, which suffered a high voltage short to ground with the location of the short obvious.  But in following the assembly steps I have found failed and missing components (some snipped out), out of spec resistors, broken terminal strips, etc. I use a yellow highlighter to mark each step in the manual that needs further attention, and penciled notes in the margin if necessary to keep track.

Boatanchor trouble-shooting and repairs can be frustrating at times.  Don't give up, just set it aside, think things over, come back to it later. The AMfone community and a 1950s ARRL handbook are good resources.
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KC3GMQ
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« Reply #28 on: March 14, 2017, 08:30:07 PM »

Just received some parts,  I will update this with my progress soon
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kc4umo
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« Reply #29 on: March 15, 2017, 02:39:30 PM »

Very interesting thread. I have another Apache I will be restoring in the near future.  Will probably add it to my lest of YouTube videos.
Should have never sold my last one.

Good luck on your repair.
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N6OIL
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« Reply #30 on: March 26, 2019, 11:43:52 PM »

Any updates?
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KJ3I
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« Reply #31 on: April 20, 2019, 11:15:57 PM »

I, too, would be interested in knowing if this transmitter has been fixed and what ended up being done with it. I am considering buying an Icom 7300 and also possibly an AM transmitter at the Hamvention next month, and this rig is one of the possible candidates for purchase.
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