[morzh]

Maybe next time

[morzh]

Now.

There was some sort of rubber sleeve that was on the tuning shaft, that transfered rotation to the tuning cap's gear, which dried and crumbled.

Will need to find a replacement, whether a makeshift solution, a rubber tube piece, or maybe the reproduction is made by someone.

Then the shadograph. Not sure if it is working or not, need to adjust light first. Maybe it does.


One thing about AK, after you dust it, it is like it has just come off the assemly line.
The speaker looks like new.

[Eliot Ness]

....There was some sort of rubber sleeve that was on the tuning shaft, that transfered rotation to the tuning cap's gear, which dried and crumbled.

Will need to find a replacement, whether a makeshift solution, a rubber tube piece, or maybe the reproduction is made by someone......

Adams Manufacturing has something listed under under their Specialty Products for A.K. tuner repairs:

http://www.adamsradio.com/

On an A.K. 92 cathedral that I have I found some thick fuel line hose I had that was the right size and used a piece of it.  If that is what you're looking for, then a trip to the local hardware or auto parts store ought to fix you up with a short piece of rubber hose with the right inside/outside diameter.

 

[morzh]

John

Thanks, yes both are viable options.
I have dealt with Adams on more than one occasion, and I like them. Prices reasonable, shipping cheap or free, product as advertised, delivered fast. What else could one wish or.


PS. Just went there, yes the part #329 looks the same. Though 808 model is not listed, from the photo I think it should fit.
I will write him first.

[morzh]

Another piece of good news, the shadograph works. It does have a resistor in parallel inside it, but 1K kinda gave me hope the coil was intact.
I had to swap the lights places, the dial one was very bright whereas the shaograph was on the dim side, so after that the shadograph became really crisp, just had to adjust the lamp hoder position.

The sensitivity is so far so-so which might be due to antenna absense, or Avc Voltage not developed proprely, will look at it.

I also thought of magnet being weak but then in the beginning it forms very thin line, and then goes almost full width, after which it settles in the middle and does react to tuning but not as much as I'd like, this is why I think the magnet is fine.

My bet is on antenna as the 2nd detector (I have yet to see where it goes to the meter but has to be it) tube is very strong.

[AI2V]

The performance of an AK808 is fantastic! The two IF stages get rid of any adjacent frequency noise and sensitivity is contest worthy. I've been using my 808 for years and use it for contesting. It's a real problem to replace EVERY wire on the band switch and IF wiring (band wiring is color coded). You also need to use an abrasive to clean the switch contacts; I use a 1/8" diam. fiberglass rod with a chisel point to scrape the crud from the rotors.

The only annoyance that small dial!

[morzh]

My switch is in good condition as it is. I might give it some profilactic Deoxit wiping but it is fine.

I do not want to align before the rubber part comes for the gear, but hopefully it 'll come soon.

[thirtiesradio]

Your coming along well on that Mike. Looking good!

I bought a 708 last week that I believe has the same chassis. After reading your posts I think I know what I'm in for

The 708 is playing. It had been recapped and has replacement wiring but it only picks up a couple stations on the broadcast band. Hopefully just an alignment or tubes.

[morzh]

if it has been rewired, you are in luck, wouldn't wish that rewiring on my enemies.
However even without alignment you should hear some activity on other bands (those where you should hear something at all), and at least changing hum/static as you rotate the dial.

But receiving anything is a good sign.

PS. The coils in AK (I have no statistics on it but just from looking at them) are not likely to have an open due to oxidation or suffer from moisture problems - they are fully potted with some tar. Which would make rewinding a miserable experience should you need to do it - how one would count turns is beyond me.

However when handling coils (only do that if you need rewiring) be a bit careful with changing wires as the wires are directly soldered to the magnet wire and potted, and the potted part of the wire is brittle.

[thirtiesradio]

Thanks Mike. I had tested it with a 6' piece of wire. I attached a much longer antenna and the other bands get activity. AM is still weak though. I will have to do some rewiring as the guy who last worked on it used the wrong wire for some of the chassis, and for all the grid wires. Looks like he ran out of cloth wire about 3/4 the way through. Very odd. Wish he had replaced the grid wires in cloth and left his handy work under the chassis.

They really stuffed this chassis in the cabinet and it weighs quite a bit. AK sure makes a quality radio.

[morzh]

Yep, looks like the same chassis as mine.

I also hated those wrapped Ground wires around the grid wires (all except those coming from the tuning cap).
Why, I ask, why......

[thirtiesradio]

Yep, looks like the same chassis as mine.

I also hated those wrapped Ground wires around the grid wires (all except those coming from the tuning cap).
Why, I ask, why......

Yes those wrapped ground wires are strange. I'm going to use cloth for the wires and then wrap it with bare wire as it was originally.

[morzh]

Well,

The single thing I couldn't quite finish so far is the alignment. Namely the IF of the 1st IF stage.
The sch is here:

http://www.nostalgiaair.org/PagesByModel...001472.pdf

I first tried the regular approach.
I found AK559 radio alignment procedure (the closest to AK808, as the 808 does not have a procedure written for it - I guess AK relied on people knowing it, on the alt. forum there was something written to that effect by AK specialists: not every AK radio has a procedure written specifically for it).
Some of it is self-evident, like IF alignment, set the generator to 472.5kHz and go.

Well, all the trimmers aligned well except the A8 (the load of the 1st IF). It first did not peak, then when I was able to peak it, it would oscillate, motorboat, howl......depending on the strength (it could not handle the small signal). It took un-peaking it for the signal to come through well. In fact radio works well this way, lots of SW, good BC.

Then I re-read the instruction - they use a balancing circuit, an RC of 0.06uF and 40kOhm in series to shunt the winding while aligning the opposite one.
Well, I had the parts, made the circuit, tried it.
No measurable difference.

they even predicted some oscillations while aligning, though with the 2nd IF stage, recommending two circuits in parallel. I did not have any problems with that one.

At any rate, with this dial a super accuracy is not needed much and it seems to be pretty close to what it should be.

BTW I probably should not touch the trimmers - they all were at peak positions...except that one I mentioned.

[morzh]

OK, I will for now consider it done, it is reasonably accurate on the dial, fairly sensitive with lots of SW without antenna etc.

Now, there is a stange way the chassis and speaker are secured.
For starters, the speaker simply hangs on the two hooks on the speaker board. I thought there should have been a screw, but no, the instruction inside explicitly says it should just hang.

The chassis is simply slid in and the knobs are installed, no screws to hold it.
They speak of some wedge but it is not there.

Sounds well.

I am tired of this radio, time to send it back to the garage where it will live 'till we move to the new place.
And....except 84, and a couple of old models (I have one, maybe 43) - NO MORE AKs.

[sam]

good job mike can`t wait to hear it in your new place  
p.s. I have an Edison radio for you to work on