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 Post subject: hickok 209a
PostPosted: Dec Tue 26, 2017 3:41 am 
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i just purchased a hickok 209a vtvm and someone cut the power cord off except for about 2 feet of it. what is left looks good no cracks or problems with insulation so im not quite sure why it was cut off. my question is does anyone know where to get the origional type wire that hickok used for these?

also i am wondering if anyone has the dc probe and the red and black probes with pin jacks used on this model they want to sell.

fortunately i have the ac probe with it so i dont have to worry about that. i do however want to test the tube in the probe and the blocking condenser in the probe. does anyone know how to take this probe apart?

i do know where to get the manual and schematic so i am good for that.

to open the meter to test tubes resistors and condensers in the vtvm i believe you just unscrew the screws on the front pannel and slide it out of its case. am i correct?

thankyou for your help in advance.


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 Post subject: Re: hickok 209a
PostPosted: Dec Tue 26, 2017 4:15 am 
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Location: Columbus Ohio
Either someone wanted the plug off the end of the cord, or it's a message not to power it up until checked out.
Yes, take out front screws, any in back for support. Get the schematics off of BAMA, replace the few capacitors,
check the resistors and solder joints throughout the unit. See if it will zero on ohms, DC+ and DC-.
http://bama.edebris.com/download/hickok ... 20209A.pdf

doubtful you will find a decent, safe and functional vintage test probe, this guy will make you a beautiful set for it.
http://stores.ebay.com/KK4HXJ?_trksid=p2047675.l2563

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 Post subject: Re: hickok 209a
PostPosted: Dec Tue 26, 2017 4:38 pm 
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Location: Long Island NY
First thing to do with these is to test the meter out of circuit. Hickok had some problems along the way with internal corrosion which results in an open coil or pointer sticking problems. If the meter is shot, it's a show stopper.

Testing the meter should always be done with a low voltage DC power source (a battery) and a resistance in series. Don't try to measure it with an ohmmeter directly as most ohmmeters pass too much current on their lower ranges.

The power cord on the Hickok 209's was a two-wire natural rubber covered type. You're not likely to find any original natural rubber cords that are still any good, so a vinyl one will be your best bet. As for the DC test probes, I would not recommend buying old, used ones for the same reason: the rubber insulation on the wire is probably going to be cracked, scuffed, have a few soldering iron burns, etc. You can buy new pin plugs, test probes, and test lead wire from some of the larger electronics distributors and make them yourself. (Pin jacks are more or less obsolete and few companies still stock new test lead sets with pin plug terminations.)

Generally speaking these meters work well once you give them a chance to warm up, but you are going to have to replace every paper and electrolytic capacitor inside, as well as some of the carbon comp resistors which may have drifted out of spec.

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 Post subject: Re: hickok 209a
PostPosted: Dec Tue 26, 2017 9:49 pm 
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Location: Jamestown NY 14701
thomas13202, wrote

also i am wondering if anyone has the dc probe and the red and black probes with pin jacks used on this model they want to sell.

Probe Master makes adapters from .093 pin jacks on the 209a to std banana.
P# 9180-4-0 blk, 9180-4-2 red about 4 bucks each. Gold plated pins on adapters.

They work great

dave

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 Post subject: Re: hickok 209a
PostPosted: Dec Tue 26, 2017 10:00 pm 
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does anyone know what the outside diameter of the origional wire was. i found some brand new ac power cords and the 16 gague cord looks like the right diameter but would be nice if i knew the outside diameter of the origional cord so i know for sure it will fit the gromet coming out of the vtvm.

re dc probe. this is shielded wire with a mic jack on one end and has a 1meg resistor in series with the probe tip. i have a ac dc probe from a bk vtvm that has the same setup but would prefer to have a dedicated probe just for this. i hope i can come across an origional probe somewhere. if the wire is bad it can be replaced.

the ground probe and the ohms current capacitance inductance probe indeed would not be hard to make if i can find pin jacks and probes with the straight tip not the new style ones with the tiny hook at the end. i find those to be a pain. i would also need some test lead.

also a kind gentleman pointed me to someone that makes custom probes. i will have to contact him and see if maybe he can make me a new dc probe.

i dont know why they didnt keep using cloth covered wire instead of the rubber covered wire. i have never seen cloth covered wire deteriorate as badly as the rubber does.


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 Post subject: Re: hickok 209a
PostPosted: Oct Sun 18, 2020 10:00 am 
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got the parts to replace the paper condensers. got what i believe is an original dc probe which looks brand new and the wire is still flexable. also a red test lead minus the probe and the alligator clip and black wire to make the negative probe. i just need the .093 male pin type plug that goes on the black wire. i cant seem to find them anywhere. any suggestions where i can locate one.

also does anyone know how to take the ac probe apart so i can change the condenser in it.

once i get the paper condensers replaced i can test the carbon comp resistors and test the electrolytics try to reform them and if i cant replace the electrolytic condensers.


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 Post subject: Re: hickok 209a
PostPosted: Oct Sun 18, 2020 1:48 pm 
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Location: Sunbury, Ohio 43074
This unit is old enough that even if the electrolytics do reform, it's not likely they will stay that way. I've restored a few of these, and all of them got new electrolytics. Hickok did not use any exceptional quality parts in these, unlike say GR or HP. In those, sometimes you can leave the original filter caps alone. I'd recommend changing these however.

A 209C black face is my bench VTVM .... mainly because I can read it without my glasses ;-)

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 Post subject: Re: hickok 209a
PostPosted: Oct Sun 18, 2020 3:37 pm 
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Location: Littleton, MA
thomas13202 wrote:
i just need the .093 male pin type plug that goes on the black wire. i cant seem to find them anywhere. any suggestions where i can locate one.

Those Amphenol large-diameter pin plugs are long out of production, so your best bets for finding one are either eBay or swap meets. The Amphenol part number for the 3/32" diameter "single prong plug" is 71-1S:
Image

However, you can home-brew one using Keystone #1224 0.93" seamless contact pins and a handle made from Evergreen styrene plastic tubing. Mouser has the pins:
https://www.mouser.com/ProductDetail/Ke ... KvJA%3D%3D

Image


ETA:
Dave, those Probemaster adapters look nice! Thanks for pointing them out.

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 Post subject: Re: hickok 209a
PostPosted: Oct Sun 18, 2020 10:38 pm 
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Joined: Jun Sat 09, 2007 8:14 am
Posts: 4308
Location: Florida
The last time I looked you could buy what's called "appliance cord" or something like that at places like Ace, Lowes, etc. It's a flexible rubber like cord that looks like the older line cords. It's sold by the foot.

As for the large pin plugs, I made some by taking the springs off banana plugs and doing a little filing to fit.

RRM


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 Post subject: Re: hickok 209a
PostPosted: Oct Mon 19, 2020 5:46 am 
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Joined: Jun Thu 25, 2015 3:21 am
Posts: 1365
thankyou to all of you for the helpfull sugestions.

i have a lead on a pair of the .080 plug. would that be to small to work with the 209a? i cant find the others mentioned in the info you sent me. like you said they probably have not been made in years.

re the cord. i will call my local hardware store in the morning to inquire if they have the appliance wire that was mentioned. trying to find anything online is a exercise in futility. search engines just dont work.

the pin plug adaptor mentioned also sounds like a good idea.


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 Post subject: Re: hickok 209a
PostPosted: Oct Mon 19, 2020 1:30 pm 
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thomas13202 wrote:
i have a lead on a pair of the .080 plug. would that be to small to work with the 209a?

Yes, they would be too small.

thomas13202 wrote:
i cant find the others mentioned in the info you sent me. like you said they probably have not been made in years.

You can buy the Keystone 0.93" seamless contact pins through the link in my previous post. Here it is again:
https://www.mouser.com/ProductDetail/Ke ... KvJA%3D%3D

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 Post subject: Re: hickok 209a
PostPosted: Oct Fri 23, 2020 9:30 pm 
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"you can home-brew one using Keystone #1224 0.93" seamless contact pins and a handle made from Evergreen styrene plastic tubing. Evergreen styrene plastic tubing. Evergreen styrene plastic tubing. Mouser has the pins:"

not sure what Evergreen styrene plastic tubing is or how you would use it to make a handle for the .093 pin. could you please explain what u mean.


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 Post subject: Re: hickok 209a
PostPosted: Oct Sat 24, 2020 4:07 pm 
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Location: Littleton, MA
thomas13202 wrote:
not sure what Evergreen styrene plastic tubing is or how you would use it to make a handle for the .093 pin. could you please explain what u mean.

If you google that phrase, you will see that Evergreen Scale Models is “the world’s largest producer of polystyrene plastic shapes”, and that it is “available at hobby shops and art supply stores worldwide”. You can also find it on Amazon.
https://evergreenscalemodels.com/

As for the handle, cut a 1 1/4” length of their #225 tubing (https://evergreenscalemodels.com/collec ... rene-tubes), which is 5/32” OD and 0.100” ID, solder the pin on the wire, slip the tubing over the wire and down to the pin, and epoxy the pin into the end of the tubing. Paint the tubing red or black, as appropriate.

Or, if you want to reproduce the look of the original Amphenol connector, buy additional tubing in the larger diameters, chosen so the 5/32” fits inside the next larger size, and so on. Then stack up an assembly of different lengths of tubing to approximate the shape of the handle on the Amphenol connector.

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 Post subject: Re: hickok 209a
PostPosted: Oct Sat 31, 2020 9:09 am 
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Joined: Jun Thu 25, 2015 3:21 am
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ok i ordered the parts to make the probes. they should be here net tuesday. then i will make the probes and change the paper condensers.

what i need to know is how do i take the ac probe apart to test the tube and change the paper cap in it. does anyone know how to do this?

thankyou for all the help everyone


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