Digest for sci.electronics.repair@googlegroups.com - 4 updates in 2 topics

9:40 AM Penedão 0 comments
Michael_A_Terrell <terrell.michael.a@gmail.com>: Sep 02 02:56PM -0400

> Thank you all for the information and suggestions. I will be able to test the concept with our big Sony CRT type TV we brought back from Saudi as it has an on-board OTA tuner with NTSC/PAL/SECAM compatibility. So, I will report back when it arrives from Ranger, TX. And. after Kutztown, I will report on range.
 
 
One thing that wasn't mentioned. The output level is +35 to +45 dB.
That can damage some TV tuners. A pair of 20 dB pads in series will give
you an output of -5 to +5 dB which is the normal range for tuners. Even
when connected to an antenna, you may want one 20 dB pad to limit the range.
 
The only 75 ohm pads that I have on hand are 6 dB. If I had any 20
dB available I would send you some. It would take seven of the 6 dB pads
to get the output into the normal range. Maybe Jeff has a couple that he
can spare,if you don't already have them?
 
A last resort is to make your own. 20 dB per stage is the most you
want to homebrew, per stage. Above that requires careful positioning of
the leads, and extra shielding.
 
RF Cafe has an online calculator for both Tee and PI types. Set the
input and output both to 75 Ohms, then enter the attenuation, per stage.
Then click the 'Calculate' button. You are probably familiar with the
formulas but some of the others who are reading the thread, aren't.
 
<https://www.rfcafe.com/references/calculators/attenuator-calculator.htm>
 
 
--
Never piss off an Engineer!
 
They don't get mad.
 
They don't get even.
 
They go for over unity! ;-)
Michael_A_Terrell <terrell.michael.a@gmail.com>: Sep 02 03:02PM -0400

Clifford Heath wrote:
> and pick it up at our warehouse" (40 minutes drive away). I've watched
> couriers delivering such notices, rather than walk the ten steps to
> the front door and ring the doorbell.
 
 
I have a Fedex account. They USED to email me the day before a
delivery was made. They don't even do that, now.
 
 
--
Never piss off an Engineer!
 
They don't get mad.
 
They don't get even.
 
They go for over unity! ;-)
"pfjw@aol.com" <peterwieck33@gmail.com>: Sep 03 05:59AM -0700

Thanks for the tip. I am not about to connect the TV directly to the modulator it will be two floors and about 100' away by direct line, and the output will be via rabbit-ear antenna. At Kutztown, I will be expected to cover a bit over two acres, and I will be feeding, almost exclusively, tube-based vintage devices. But if I overload the Sony, I will snag (an) F-connector pad(s) as needed.
 
Thanks again!
 
Peter Wieck
Melrose Park, PA
amdx <amdx@knology.net>: Sep 02 12:51PM -0500

On 8/31/2020 2:18 PM, Roy Buskirk wrote:
 
> Can anyone tell me what these 4 leads do and how to reconnect them, once the SCGFP potted module is removed.
> My purpose is to convert this transformer for use as a Fractal Wood Burning System
> Thank you - Roy
 
 I'm assuming since its old, it is all wire.
 
No Idea, but is there continuity between blue and bl/wh ?
 
B/W and OR?
 
Or and OR/W?
 
Which ones have the highest resistance?
 
 Does BL and BL/W have equal resistance to OR and OR/W?
 
 Curious minds want to know.
 
                                    Mikek
 
 
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Digest for sci.electronics.repair@googlegroups.com - 9 updates in 2 topics

9:40 AM Penedão 0 comments
Fox's Mercantile <jdangus@att.net>: Sep 01 12:04PM -0500

On 9/1/20 11:19 AM, Michael_A_Terrell wrote:
> Let me know if that doesn't pan out.
 
I am sending Peter a Blonder Tongue Agile Modulator.
Model: AM 40-450 Stock No. 59406.
Complete with a manual for setting the output channel
dip switches.
 
 
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
"ohg...@gmail.com" <ohger1s@gmail.com>: Sep 01 11:07AM -0700

On Tuesday, September 1, 2020 at 1:04:50 PM UTC-4, Fox's Mercantile wrote:
> Model: AM 40-450 Stock No. 59406.
> Complete with a manual for setting the output channel
> dip switches.
 
Nice. It would appear that you are not the prick most people in other hemispheres would have us believe.
 
Many many moons ago when cable TV was still analog, I put an A/B switch on the main line of my cable and used the B side to feed my distribution amp in which the output was connected to a set of rabbit ears and the A side to feed the cable box. That setup broadcast the whole VHF spectrum to any TV in the shop I would put a clip lead to. One day the cable guy comes in - they had been driving around "sniffing" for leakage, and my store was a real hotspot. He thought I had an open ground, but I told him I knew where the bad crimp was and threw the switch to A and the problem went away. The next day I went back to using the B side and a couple of months later they came in again, so they must have sniffed routinely , so I abandoned the plan. I should have tried broadcasting the output of the box alone - maybe they wouldn't have bothered me if it was a narrow spectrum.
Michael_A_Terrell <terrell.michael.a@gmail.com>: Sep 01 04:20PM -0400

Fox's Mercantile wrote:
> Model: AM 40-450 Stock No. 59406.
> Complete with a manual for setting the output channel
> dip switches.
 
 
That is a well made Agile modulator with a decent VSB filter before
the upconverter. My comment wasn't meant to imply that he wouldn't get a
modulator, just in case something happened to it. Too much stuff is
being lost or damaged in shipment these days. Fedex just lost a Sadelco
FSM of mine. The love to leave my packages at similar addresses on other
streets. Some of the old analog FSM have a crude but useful Spectrum
analyzer mode built in. Peter might even want more than one modulator,
on adjacent channels, to show how old TVs deal with Intermod and
Co-channel interference.
 
I finally have a HP 1.3 GHz counter to fill in the gaps in the
programming chart for that model. I believe it goes down to the T
channels, that were used for reverse feed but I can't access my outboard
drives until I complete electrical repairs. An open neutral from the
pole pig fried most of my equipment, and all of the surge suppressors on
one phase. I currently have one working 20A single phase circuit and a
lot of dead equipment after that phase went over 165 volts.
 
As usual, the utility just rolled their eyes when I told them the
neutral was open. They sent an automated call just before midnight,
canceling the service call, since their so called 'smart meter' reported
that I had power. They don't report an open neutral. I had to threaten
to report them to the PUCO when I called back, before they actually sent
out a truck. Once again, I got attitude, then the lead tech saw the bare
neutral arcing where it had broke. That drop was installed in 1964.
 
--
Never piss off an Engineer!
 
They don't get mad.
 
They don't get even.
 
They go for over unity! ;-)
Fox's Mercantile <jdangus@att.net>: Sep 01 03:26PM -0500

On 9/1/20 3:20 PM, Michael_A_Terrell wrote:
> Too much stuff is being lost or damaged in shipment these days. Fedex
> just lost a Sadelco FSM of mine. The love to leave my packages at
> similar addresses on other streets.
 
Signature required makes a lot of difference.
 
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
Michael_A_Terrell <terrell.michael.a@gmail.com>: Sep 01 04:29PM -0400


> Nice. It would appear that you are not the prick most people in other hemispheres would have us believe.
 
> Many many moons ago when cable TV was still analog, I put an A/B switch on the main line of my cable and used the B side to feed my distribution amp in which the output was connected to a set of rabbit ears and the A side to feed the cable box. That setup broadcast the whole VHF spectrum to any TV in the shop I would put a clip lead to. One day the cable guy comes in - they had been driving around "sniffing" for leakage, and my store was a real hotspot. He thought I had an open ground, but I told him I knew where the bad crimp was and threw the switch to A and the problem went away. The next day I went back to using the B side and a couple of months later they came in again, so they must have sniffed routinely , so I abandoned the plan. I should have tried broadcasting the output of the box alone - maybe they wouldn't have bothered me if it was a narrow spectrum.
 
 
That stunt could have wiped out communications for emergency
vehicles on the VHF high band, the two meter ham band and airports. You
could have indirectly caused people to die. We had people do that in
Apartment buildings, near Cincinnati. We had to install monitors in all
of our trucks to find them as soon as possible. If the FCC got involved,
it could have lead to time in prison. Cable TV uses those frequencies on
a shared basis, under the condition that leakage levels be maintained.
On big problem was morons slipping 300 ohm flat antenna cable under a
carpet, to move the TV to another location. It could be detected from
blocks away. Our sniffer system was outdated, but the video carrier for
MTV was on the right frequency so we could still use the receivers.
 
 
--
Never piss off an Engineer!
 
They don't get mad.
 
They don't get even.
 
They go for over unity! ;-)
Michael_A_Terrell <terrell.michael.a@gmail.com>: Sep 01 04:35PM -0400

Fox's Mercantile wrote:
>> just lost a Sadelco FSM of mine. The love to leave my packages at
>> similar addresses on other streets.
 
> Signature required makes a lot of difference.
 
 
I was told it was being shipped by USPS. They told the seller that
they had over a two week backlog, and to use anyone else. I wasn't given
the choice. Fedex often delivers after 9PM, which doesn't help. UPS
often gets here after dark, as well.
 
 
 
--
Never piss off an Engineer!
 
They don't get mad.
 
They don't get even.
 
They go for over unity! ;-)
Clifford Heath <no.spam@please.net>: Sep 02 02:49PM +1000

On 2/9/20 6:26 am, Fox's Mercantile wrote:
>> just lost a Sadelco FSM of mine. The love to leave my packages at
>> similar addresses on other streets.
 
> Signature required makes a lot of difference.
 
Yeah. Instead of an incorrect delivery, you get a note in the mailbox
saying "We tried to deliver but no-one answered the door. Please come
and pick it up at our warehouse" (40 minutes drive away). I've watched
couriers delivering such notices, rather than walk the ten steps to the
front door and ring the doorbell.
 
CH.
"pfjw@aol.com" <peterwieck33@gmail.com>: Sep 02 06:58AM -0700

Thank you all for the information and suggestions. I will be able to test the concept with our big Sony CRT type TV we brought back from Saudi as it has an on-board OTA tuner with NTSC/PAL/SECAM compatibility. So, I will report back when it arrives from Ranger, TX. And. after Kutztown, I will report on range.
 
Thanks again!
 
Peter Wieck
Melrose Park, PA
Kariman Jader <karimanj12@gmail.com>: Sep 01 05:34PM -0700

Please send me
Solution manual Principles of Environmental Engineering and Science (3rd Ed., Mackenzie Davis & Susan Masten)
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Digest for sci.electronics.repair@googlegroups.com - 8 updates in 2 topics

9:40 AM Penedão 0 comments
Three Jeeps <jjhudak4@gmail.com>: Aug 31 12:41PM -0700


> Thank you!
> Peter Wieck
> Melrose Park, PA
 
A few years ago, I used an RF amp from these folks and it worked well. In the VHF range, the amps they have are relatively low power 1-3 W. Would something in that power range be sufficient?
https://www.pasternack.com/medium-gain-medium-power-amplifiers-category.aspx
Michael_A_Terrell <terrell.michael.a@gmail.com>: Sep 01 12:34AM -0400

> Some here may know that I operate the Part-15 compliant AM & FM transmitters for the Kutztown Radio Meet. Given that vintage TVs are becoming more prevalent at the show, I would also like to operate a small VHF television transmitter featuring vintage movies and such. I see lots of stuff out there for UHF, nothing that specifically lists VHF, other than DIY stuff, for which I have neither the time nor inclination given I do not collect any sort of TV stuff.
 
> Kit or ready-made - any suggestions? Remember, I am in the USA.
 
Blonder Tongue and Holland agile or fixed channel modulators sell cheap
on Ebay. They put out enough RF that you may not need a power amplifier.
I've bought them for $15 plus shipping. R.L. Drake also built them.
Pico, Microdyne and others built them for MATV headends and they are all
are basically obsolete since 2009. RCA, Scientific Atlanta and Phasecom
built them for CATV headends. These sold new for thousands, but there is
little to no marlr them.
 
Some can also put out their Aural carrier on the old 49 MHz FM band.
You would need a trap to kill the video carrier.
 
There are lots of five for $30 on Ebay, right now. They are without
the power supply, rack and combiner, but you only need power for one of
them. I don't know what channels they have left, but the seller is
E-cyclePro. They often have these items.
 
 
 
http://www.ebay.com/usr/e-cyclepro
 
https://www.ebay.com/itm/283848841569 has one on Ch9 for $27
 
Holland-HPM55-Audio-Video-Modulator-Tested-Commercial
 
If you want to drive multiple lines, there are sometimes one in, 16 out
broadband distribution amplifiers for under $50. With the high output
level of a MATV modulator you could use a four way splitter, each split
four ways to drive up to 16 TVs without an amplifier. That would require
running a lot of RG59/6/11 coax. With the amplifier you could scatter a
few antennas around and use rabbit ears on the TVs with a lot less coax.
 
I have a new, in the box Tradewind Rack Mounted Distribution Amplifier
for $35, but i don't think that you really need it.
 
 
 
--
Never piss off an Engineer!
 
They don't get mad.
 
They don't get even.
 
They go for over unity! ;-)
"pfjw@aol.com" <peterwieck33@gmail.com>: Sep 01 05:57AM -0700

Thank you! I am going in this direction, with thanks to a certain individual who happens to have such a device, and is willing to pass it along.
 
Peter Wieck
Melrose Park, PA
Michael_A_Terrell <terrell.michael.a@gmail.com>: Sep 01 12:19PM -0400

> Thank you! I am going in this direction, with thanks to a certain individual who happens to have such a device, and is willing to pass it along.
 
 
See if you can find a good image of the old test pattern and burn it
to a DVD. That will help people see how sharp the image really is. It
will also show poor IF alignment that was done with crude Sweep/Marker
generators rather that a multiburst system.
 
Let me know if that doesn't pan out. I am familiar with a lot of
brands and models of modulators. I have a nearly complete analog headend
system, in storage. I just need a couple full height relay racks, and
dipexers for 60 channels! :)
 
At one time my job was to repair headend equipment for a top 100 MSO
cable group. We also up linked WGN, WOR and operated the first
Electronic Program Guide on a subcarrier on our WGN transponder. We also
had WFMT on another WGN subcarrier.
 
Sigh. That was 35 years ago. I did over 10,000 repairs, in four
years including microwave equipment the OEMs refused to support.
 
 
Never piss off an Engineer!
 
They don't get mad.
 
They don't get even.
 
They go for over unity! ;-)
Roy Buskirk <datamatrix65@gmail.com>: Aug 31 12:18PM -0700

I have an older FRANCE PG-1 Series neon sign transformer. It is a type that contains a SCGFP potted module in top compartment of transformer. There are a number of leads originating from the potted transformer, which I am trying to identify.
 
3 of the leads, black, white and green, ring out as extensions from the input power posts. This is the 120 VAC supply to the unit.
 
There are 4 remaining leads
(1) blue,
(1) blue with white stripe,
(1) orange,
(1) orange with black stripe
 
Can anyone tell me what these 4 leads do and how to reconnect them, once the SCGFP potted module is removed.
My purpose is to convert this transformer for use as a Fractal Wood Burning System
Thank you - Roy
Trevor Wilson <trevor@rageaudio.com.au>: Sep 01 06:03AM +1000

On 1/09/2020 5:18 am, Roy Buskirk wrote:
 
> Can anyone tell me what these 4 leads do and how to reconnect them, once the SCGFP potted module is removed.
> My purpose is to convert this transformer for use as a Fractal Wood Burning System
> Thank you - Roy
 
**I doubt that it will deliver sufficient current to burn wood. Use a
(couple of) microwave oven transformers.
 
--
Trevor Wilson
www.rageaudio.com.au
 
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Terry Schwartz <tschw10117@aol.com>: Aug 31 04:09PM -0700

On Monday, August 31, 2020 at 3:03:29 PM UTC-5, Trevor Wilson wrote:
 
> --
> This email has been checked for viruses by Avast antivirus software.
> https://www.avast.com/antivirus
 
Better yet, don't even try. It's super dangerous.
Trevor Wilson <trevor@rageaudio.com.au>: Sep 01 11:09AM +1000

On 1/09/2020 9:09 am, Terry Schwartz wrote:
>> This email has been checked for viruses by Avast antivirus software.
>> https://www.avast.com/antivirus
 
> Better yet, don't even try. It's super dangerous.
 
**Oh yeah. There is that.
 
--
Trevor Wilson
www.rageaudio.com.au
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