Raccoon1400
Super Member
The sencore arrived today. The tuning gang is stuck, it only moves a little bit. I think the grease in the bearings has clumped. Does anyone know how to fix this?
Tools for alignment
- Thread starter Raccoon1400
- Start date
Raccoon1400
Super Member
I unstuck it. I sprayed a bit of deoxit in the bearings and it moves now. I also found 2 leaking caps.
dr*audio
Fish fingers and custard!
You should really flush the old grease out of the bearings with a non - residue degreaser / contact cleaner, then re - lube them with white lithium grease.
fortycoats
Super Member
Hmm, it was a while ago so can't remember my frame of mind at the time but my previous post now reads back to me like a bit of a whinge (to put it mildly) so sorry about that folks. However, the subsequent posts from terra1, MX117.MC1750 and Bob@FM have finally made me understand why I don't see loads of sites out there with generic steps for this stuff. They also made me realise that I've been part of my own problem in holding myself back by assuming it's far too difficult to even attempt. So, you know what, I'm gonna try one! Thanks guys. :thmbsp:
terra1
Addicted Member
By "interpreting the circuits" it's important to determine what it does. For example depending on the manuals, some will refer to an OSC adjustment that will move the station up or down the scale for calibration. You need to note if it is a clockwise or counterclockwise turn so you can turn the tuning knob up or down the scale to find it again if you lose it. This is where a lot of finesse (difference between nudging instead of turning) and patience comes in. Some adjustments you can see the correlation between adjustments by how the meter needles respond or when the Stereo indicator comes on.
dr*audio
Fish fingers and custard!
Digi-key has them but they are hard to find with their search engine. I think the company that makes the good ones is Aven. The good ones are made of Delrin. The others are made of some cheap soft plastic and the bits get stripped. There are some square drivers that are used for Yamaha and others that are not in the Aven kit. I can't remember where I found that one.
TR6man98
Well-Known Member
Warren,
This was really helpful! Thank you.:thmbsp:
Apparently Avon alignment tools are ceramics and bellow is link to their website to help others in the future:
http://tinyurl.com/3olavtn
http://aventools.thomasnet-navigator.com/category/alignment-tools
Delrin search is somehow linked to GC Electronic and some tools are here:
http://tinyurl.com/3nxcl6c
BTW, this is a great thread and a good read. Also your Tuner cleaning sticky helped me “restore” reception in three tuners and receivers (one being Mac MR74). All are working flawlessly now, however didn’t lead to desired results on Marantz 4240, therefore my interest in alignment procedures.
There’s more of it on Marantz forum and how to DIY; I might try it but I already have someone identified who can do that here, in Seattle.
Soon, after my vacation…
Regards,
This was really helpful! Thank you.:thmbsp:
Apparently Avon alignment tools are ceramics and bellow is link to their website to help others in the future:
http://tinyurl.com/3olavtn
http://aventools.thomasnet-navigator.com/category/alignment-tools
Delrin search is somehow linked to GC Electronic and some tools are here:
http://tinyurl.com/3nxcl6c
BTW, this is a great thread and a good read. Also your Tuner cleaning sticky helped me “restore” reception in three tuners and receivers (one being Mac MR74). All are working flawlessly now, however didn’t lead to desired results on Marantz 4240, therefore my interest in alignment procedures.
There’s more of it on Marantz forum and how to DIY; I might try it but I already have someone identified who can do that here, in Seattle.
Soon, after my vacation…
Regards,
MX117.MC7150
Listener
Warren is definitely one of our top "known good" tuner techs and persons.
If I may add some background, it might help everyone who is interested in FM and/or FM MPX alignments. I'm one of those members who usually suggests that if you're asking these questions, you're not ready, and if you attempt this work, you will not be happy with the outcome. And I fully admit that although I'm a long, long way from being a beginner in electronics, I'm absolutely not ready to even try to do an FM MPX alignment. And I've actually had a class in RF theory.
Here's why: You can recap an amplifier without knowing what capacitors do. You can recap an amplifier without understanding amplifier circuits at all. You can recap an amplifier by following a simple set of "How-to" instructions, learning how to solder, and being careful of safety considerations. If you know how to use basic test equipment, you can learn how to align AM radios. Although it would help if you understood what modulation is and what an intermediate frequency is, it's not entirely necessary.
FM, on the other hand, is an entirely different kettle of fish. And FM multiplex really is rocket science compared to recapping an amplifier. I'm struggling to come up with an appropriate example to make the point, but it's difficult.
"I'd like to learn how to rebuild the Rochester mechanical fuel injection system in a 1962 Corvette. If I buy all the right tools, can you walk me through how to do it?"
No.
If you want to learn how to do FM MPX alignments, you really do need to understand frequency modulation, multiplexing, and how the information in an FM MPX signal is transmitted and then decoded in a receiver. If you don't understand that, then you will have no idea what you're doing when you try to make the squiggly lines on a scope look like what the pictures show they're supposed to look like. Knowing how to read a schematic and having a service manual isn't enough.
Here is an overview of basic FM alignment suggestions. Scroll down to the "January 2010 update":
http://www.fmtunerinfo.com/
Here are two basic "hands-on" threads:
http://www.antiqueradios.com/forums/viewtopic.php?t=132980
http://antiqueradios.com/forums/viewtopic.php?t=130054&highlight=alignment+sweep+pictorial
Overview of the Sencore SG-165:
http://antiqueradios.com/forums/viewtopic.php?t=129016
It would also be a very good idea to join the FMtuners group on Yahoo.
FM alignment is a fascinating topic, and learning to do it well is an admirable goal. However, there are many intermediate steps one must go through beyond knowing how to replace parts and use test equipment before you can attempt this work.
Hope this helps a bit.
(As always, the real experts, as opposed to the wannbes like me, are welcome to chime in.)
I will chime in, not as a tuner expert, but someone that has taught himself how to properly align certain tuners that matter to me, over the past several years.
JUST DO IT!
Read the tutorials, pick up something like an SG-165, get an inexpensive set of plastic alignment tools, find a reasonable candidate for an alignment that you can also find a service manual for, and get engaged. Like many things in live, doing it will teach you way more than reading about doing it.
This is not rocket science, and lives are not lost if you get it wrong the first time... or the second, or third.
The learning curve certainly exists but it's fun to climb and there are plenty of experts around here to ask for assistance as you climb it, if you need the push up.
John
P.S. Never worked on a Rochester injection system but learned over the years how to keep Bosch K-Jetronic systems and the mechanical injection on my M130 Mercedes engine working. If you have the car, a manual, tools, determination and patience, it's going to happen. Tuner alignment is much the same, IMHO.
JUST DO IT!
Read the tutorials, pick up something like an SG-165, get an inexpensive set of plastic alignment tools, find a reasonable candidate for an alignment that you can also find a service manual for, and get engaged. Like many things in live, doing it will teach you way more than reading about doing it.
This is not rocket science, and lives are not lost if you get it wrong the first time... or the second, or third.
The learning curve certainly exists but it's fun to climb and there are plenty of experts around here to ask for assistance as you climb it, if you need the push up.
John
P.S. Never worked on a Rochester injection system but learned over the years how to keep Bosch K-Jetronic systems and the mechanical injection on my M130 Mercedes engine working. If you have the car, a manual, tools, determination and patience, it's going to happen. Tuner alignment is much the same, IMHO.
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kevzep
Its all about the Music
I have to agree with this, and you know if you are an intuitive person, it is entirely possible. This is how I have learned....
I am actually a qualified/certified car mechanic.....I left the trade 22 years ago....
But I have found that learning electronics is very similar, especially with regards to servicing and fault finding....its a similar mindset......I have always had an interest and an aptitude for electronics so it all comes fairly naturally.....
With regards to whats going on here, yes tuners are difficult, because you do have to understand how they work to align them, you have to know what it is you are looking for when you are adjusting.....
All this is fine until you have an FM tuner with a fault..
Aligning a fully healthy tuner is one thing, trying to align one with a fault which you are not aware of, is something only knowledge and experience see you prevail.......
My two cents....
Raccoon1400
Super Member
I have an hk 430 that I want to start with. It looks like a good simple one to start with. I have a couple questions.
The service manual for the hk says "connect signal source to a loop placed to radiate signals into AM ANT LOOP STICK." How do I do this?
I'm not clear on how to setup the sencore.
The hk service manual says "AM signal generator modulated with 400Hz at 30%"
The first step says "455kHz of sweep generator AM sig. gen." Then 530kHz, etc...
I see I set the am modulation switch to 30%. After that I'm not sure. The AM tuning dial only goes as low as 526kHz.
The sencore manual says to "Connect the SG165 speaker loads". What are these? How do I connect them? Are they the alligator leads in the lead compartment in the back? Or would it be better to use my scope for analysing the output?
The service manual for the hk says "connect signal source to a loop placed to radiate signals into AM ANT LOOP STICK." How do I do this?
I'm not clear on how to setup the sencore.
The hk service manual says "AM signal generator modulated with 400Hz at 30%"
The first step says "455kHz of sweep generator AM sig. gen." Then 530kHz, etc...
I see I set the am modulation switch to 30%. After that I'm not sure. The AM tuning dial only goes as low as 526kHz.
The sencore manual says to "Connect the SG165 speaker loads". What are these? How do I connect them? Are they the alligator leads in the lead compartment in the back? Or would it be better to use my scope for analysing the output?
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dr*audio
Fish fingers and custard!
These instructions are for the AM alignment. 455KHz is the AM IF center frequency. You set the generator to 455KHz and connect the generator to the input of the 1st IF amplifier. I used a Sencore many years ago and I don't remember much about it. I think you have to connect your scope up to the Sencore and I think the Sencore came with a detector probe to connect to the output of the last IF amp. The instructions should describe the waveform you need to tune for. Basically you tune the IFs for maximum signal strength. You can use the tuning meter on the tuner itself. Then you should use a distoortion analyzer to tune the detector for minimum distortion.
If you don't have a distortion analyzer you have to use a scope, and adjust for maximum amplitude and minimum distortion on the sine wave (for AM.) For FM alignment you will have to use a scope and connect it to the Sencore, Set the Sencore up for Sweep Mode and adjust the discriminator coils for the waveforms shown in the Sencore manual. To align the FM IF you would use the detector probe and adjust for the waveforms shown in the Sencore manual.
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Raccoon1400
Super Member
Raccoon1400
Super Member
yes, I have a pdf. I mentioned it in my last post, about the speaker loads.
You can use the speaker connections as an output and do separation adjustments. If you have an oscope you can take the output of the tuner or if its a receiver the tape output.
Did you get the matching transformer with the Sencore? It's tube with three clipped leads. Black and red are 75ohm, Green and Red are 300ohm. For AM you can use a loop antenna, the Red and black lead and loop the antenna over your bar antenna to inject the amp RF to the tuner.
If you didn't get one, there's a scat in the manual you will will need to build one.
Did you get the matching transformer with the Sencore? It's tube with three clipped leads. Black and red are 75ohm, Green and Red are 300ohm. For AM you can use a loop antenna, the Red and black lead and loop the antenna over your bar antenna to inject the amp RF to the tuner.
If you didn't get one, there's a scat in the manual you will will need to build one.
Susurus
Resolution:6.62×10^-34
On an ADD-OCD scale, do you rate a 10?
EE departments nowadays might focus on digital. Etech classes might still have an instructor with hands-on knowledge of the analog realm, so ask around and take some electives maybe...could be good for your GPA too... :thmbsp:
EE departments nowadays might focus on digital. Etech classes might still have an instructor with hands-on knowledge of the analog realm, so ask around and take some electives maybe...could be good for your GPA too... :thmbsp: