2019-05-24 IR Slave Flash

I had an old RCA TV with an early remote control that used an IR beam with different frequencies for 6 different functions. I also had a VCR with the newer remote that sent the codes digitally over a 38kHz carrier. I built a remote extender so I could use both remotes beyond their short range. The problem was the remotes were totally different, so I made the extender so it was just a preamp and output so whatever came in was what it sent out to the IR LED 20 feet away,, and it worked well with both remotes. What went in was essentially what came out.

I thought this same method would be a good way to make an IR slave flask.


2019-05-22 Fiber Installing In Near Future

from FB group Orange Talk May 23

What I’ve seen is the internet service providers have eliminated the lowest speeds and lowest prices of course, and now offer only higher speeds and higher prices. For the city of Orange, there will be at&t fiber cables installed in the near future, so Sputum cable will have some hard competition, but when new infrastructure is installed the company has to recover costs so it may not be soon until prices drop. Only time will tell.


2019-05-21 Upstream Data Concentration

from FB group Bell Telephone… May 22

Keith Hlavacs
I was connecting up equipment with cat5e and cat6 cabling capable of 1000 Meg’s, and there were 48 ports on the switches on campus. The GBIC feeds on, say, 4 switches were daisychained, so a total of 192 ports per fiber optic feeder. So…

I see so much advertising about 100 Meg’s but we all know that as it goes upstream, there is concentration, so a home is sharing 1G or 10G feeder with dozens or scores of neighbors. So is 100 Meg’s just advertising or can all of your neighborhood actually get it at the same time?


2019-05-19 No Go Showboat

from FB group regenerative receiver initiative May 22

Henrik Stenstrom
I would like to build something hollow state with all sorts of gizmos like in this photo, but all of it would be a no-go showboat, just for looks. I would put Amber or orange LEDs under the tubes to make them look like they’re powered up. The actual active circuits would be all solid state and hidden from view.


2019-05-17 March of technology Kills Skills

from FB group Bell Telephone of.. May 18

Bob Rosa
Said “The march of technology inherently takes the skill out of every trade.”

The existing skills may be taken out, but it adds new skills. Yes, that trade as a wire splicer may no longer be needed, instead there will be a much greater demand for fiber optic cable splicers. Just ask Andy Krop, who is training on a new fiber optic network. This is nothing new. Remember you no longer had to solder splices, trading it for a punch down tool. 👍


2019-05-09 A 3V to 9VDC Boost Converter V. 1.1

I built this in 2007. No load it puts out 9.5VDC and at 22 mA it puts out 8.5VDC. It works okay for powering a radio on the FM band, but it has too much RF Interference on the AM band. The original circuit had only a single output transistor but it couldn’t handle enough current so I added the little PCB with four BC338 transistors in parallel. I extended the wires for the coil so I could experiment with different toroid coils. The one in this photo is two FT37-43 cores stacked, with about 18 turns of 26 AWG wire, measuring 250 microhenrys. The black and white output wires are wound around a RFI suppressor sleeve before exiting the case, but this is not enough to remove the RFI. There need to be more chokes outside to reject the RF interference before the radio will be able to pick up stations. I added those filters and the radio receives the AM stations with a slight amount of hash between stations.

Some call this a Joule Thief circuit, but it does not have a second winding on the coil so


2019-05-08 Dad’s Barber Shop In Stock Yards In Vernon, CA

Most of this was in FB group Compton 50s 60s

My dad’s barber shop was in the old Stock Yards in Vernon. He used to take me there on Saturdays and we’d drive by the murals of Farmer John and his livestock on the walls along Bandini Blvd, IIRC. I used to climb on the big boulders (to me at that time; I was just a kid) that were a monument to a battle that had taken place long ago where the Stock Yard was. When they tore down the Stock Yards they moved those boulders to the entrance in front of the Vernon P.D. at the City Hall (see photo below). Some day I’ll have to go there and take a selfie of me on those boulders. 😁

Another unforgettable place near there was where Dad took us; it was the Bethlehem Steel plant near there. Some called her Lady Beth because the plant was a place in the poorer part of town where one could get a good job. This steel plant was a huge building with a roof but the sides we’re open to the air. When you saw what was done there you could understand why. There was a big furnace to heat big billets of steel weighing many tons. The furnace lid would slide open and a gantry crane would reach in and pull one out and when it came out we could feel the heat on our faces in the car parked a few hundred feet away. The crane would lay this huge yellow-orange hot billet on to a


2019-05-05 Using a 7805 For An Adjustable Regulator

from FB group Building Transistor Radios

Willie Barnett
When you understand how the 3 terminal regulators work, you can replace the 1N4148 and the almost impossible to get 1N34 with just a pair of resistors.

The 7805 or 78L05 regulator always has a fixed voltage of 5V between the O and G pins. So you turn this into a constant current source by putting a resistor, 1k, between O and G. Now you have a constant 5/1000 amp going to ground. There is a very small .05 mA coming out of the chip itself, which is only 1 percent of the 5 mA through the 1k resistor.

So if you want to increase the output voltage by 2V to 7V output, you put another resistor in series with the ground, just like the adjustable LM317. To add 2V, you calculate this resistance as 2V / .005A, which is 400 ohms. So use the closest value, 390 ohms. Your output will then be 7 volts. Or you can use a trimmer for adjusting to any voltage.

Another way would be to put a red LED in place of the resistor to ground. This should give about 1.8 to 2V drop. But the LED has a temperature coefficient that gives a lower voltage as the temperature increases. The resistor is more stable and so is the voltage.


2019-05-02 Regen Using PN2222A Connected Backwards

from FB group Regenerative Rcvr Initiative May 3

Cyril Hodson
Superregen receivers are always past the point of regenerative amplification. The AGC for a Regen should keep the regen high but prevent it from oscillating.

I was thinking that a CdS photocell could be put in series with the Regen pot, and light from a LED would shine on the photocell. The LED would be driven by the rectified and filtered signal from the detector.

I’ve had poor success with regens, and I recently read a project that may have the answer as to why my regens are so bad. One ham said that another Regen builder connected a PN2222A backwards (swapped E and C) so that it would have low gain. This makes it regenerate much smoother. All these years I’ve been under the invalid idea that higher gain is better. Another way to approach this is to use a JFET which has lower gain than a BJT.

David Wayne Cripe
Grounded base is low impedance input and high impedance output and some of the loss of gain is from mismatch of impedances. But what’s really good about grounded base is the input is isolated from the output, so it keeps the regen signal from coming out of the antenna. 👍


2019-04-29 Center Tapped Voice Coil And OTL Circuit

from FB group Vintage Transistor Radios Apr 29

Robert Abend
Yeah, thanks for bringing that up. Many of the GE radios have a center tapped coil in their armature speakers. I never really thought about the unusual CT voice coil. The most important reason why is that a voice coil moves and has to be light to maximize the frequency response. The reason for center tapping is to eliminate the output transformer. But the primary of the OT has higher impedance, which means many turns of fine wire. That’s more difficult to make light and difficult to wind on a piece of thin paper. That’s why the armature is used – it’s much easier to wind.

But all this was made moot by the complementary symmetry OTL ‘totem pole’ circuit, which drives lower impedance loads. By the 1960s this was very common in audio amplifiers. No output transformer, so manufacturing cost was lower.

© RustyBolt.Info/wordpress