[Thursday] Suggested Radio-Related Interactive Exhibits

Mon Aug 26 13:33:27 MDT 2019

I like this. Fits in with the Morse code demo; involves a minimal amount of
(unexplainable) magic; totally harmless and cheap. Could easily be expanded
to teach some basic electricity. Encourages experimenting: more batteries
(series or parallel?)=more distance or louder static? Effect of coin
size? Could
it work with a switch/key? Could you add an antenna/radiator? Can you
receive it with a crystal radio?

On Mon, Aug 26, 2019 at 6:37 AM Craig Moody <cmoody3453 at gmail.com> wrote:

> Here's another idea for a hands-on simple radio transmitter that may pique
> a visitor's curiosity.  I found this cool little demonstration online:
>
> By tapping the terminals of a 9-volt battery with a coin, you can create
> radio waves that an AM radio can receive.
>
> 1) Take a fresh 9-volt battery and a coin.
>
> 2) Find an AM radio and tune it to an area of the dial where you hear
> static.
>
> 3) Now hold the battery near the antenna and quickly tap the two terminals
> of the battery with the coin (so that you connect them together for an
> instant). You will hear a crackle on the radio that is caused by the
> connection and disconnection of the coin. Your battery/coin combination is
> a radio transmitter! It's not transmitting anything useful, just static,
> and it will not transmit very far, just a few inches, because it's not
> optimized for distance.
>
> 4) If you use the static to tap out Morse code, you can actually
> communicate over several inches with this crude device!
>
> Craig
>
>
> On Mon, Aug 26, 2019 at 12:06 AM Randall Snow via Thursday <
> thursday at newsm.org> wrote:
>
>> Guys,
>>
>> These are great ideas and I think we're starting a discussion that will
>> have a huge impact in the years to come.  Ken, your list and component
>> aspects are very thorough and engrossing.  Dave, you've summarized years of
>> discussions and have a keen eye on all the possibilities for the museum's
>> evolution.  Also, the website for the Exploratorium is great, and they have
>> a lot of resources there we can explore.
>>
>> A lot of this has to do with the long-term plan for the museum, and of
>> course will be years in the making.  With Steam-Up on the horizon, we don't
>> have a great amount of time, but I think one or two of these could be
>> rolled out in primitive form at least.  I'm thinking we make it something
>> quick and effective.
>>
>>  A couple of versions of early radios that people can actually tune into
>> a modern broadcast would be great.  Something as incredibly simple as a
>> crystal set would be amazing to show what little you really need to receive
>> a signal.  I'm hesitant to add in any sort of amplifier just because it
>> detracts from the simplicity and could have people confused about what's
>> going on in the black box.  Getting sound with some coils of wire, a chunk
>> of rock ( or razor blade, or 1 diode) and no batteries will undoubtedly
>> astound most folks.  Then of course adding a few steps of evolution in,
>> open and working for people to play with, would be great.  Along with this,
>> if there is time, and if we have the manpower for Steam-Up, we can probably
>> run the "build a foxhole radio" session a couple of times during the day.
>> I'm a little torn on the typical razor blade idea.  I think the only way we
>> could do that safely would be to glue them down to the base board ahead of
>> time so they couldn't be handled.  I can also get blue tempered spring
>> steel sheet in just about any thickness that we could cut up.  I'm just
>> guessing that we could get that to work in the same fashion as a razor
>> blade.  The other idea, safer and quicker, is just to use a modern diode in
>> it's place.  It could be explained or even demonstrated to them how it
>> would be done with the blade and pencil, and how a diode serves the same
>> modern day function.  At that point they are being shown a tie to something
>> more modern too and the functional relationship.
>>
>> The radio tuning could be done in the wireless building, among the radios
>> that are there, or upstairs in Massie.  Foxhole radios could be done
>> outside if the weather cooperates or possibly in Mayes.  Let's think about
>> these a bit more and see if there is time to make them happen or not.
>>
>> Thanks, and I'm excited to see where the whole discussion leads!
>>
>> Randy
>>
>>
>> On Sun, Aug 25, 2019 at 4:35 PM David Caldwell via Thursday <
>> thursday at newsm.org> wrote:
>>
>>> Just a few thoughts in no particular order.
>>>
>>> 1. Some exhibits can be engaging without being interactive. Some people
>>> like to play with stuff; some people like to look, read and figure stuff
>>> out.
>>> 2. Many visitors, especially on busy days like Steam-Up, won't be with a
>>> docent and won't take the time to sit down. We need some exhibits that are
>>> 'self-service. (This is related to #1.)
>>> 3. It's important to decide at the beginning of planning who the
>>> audience is for a particular exhibit. Every exhibit has to assume some
>>> things about it's intended audience--what ideas they are familiar with,
>>> what language can work for them (eg, vocabulary, complexity), physical
>>> dexterity, etc.
>>> 4. We need to consider potential accessibility issues.
>>> 5. We need to consider safety always. Safety of the visitors, and safety
>>> of the artifacts and exhibits.
>>> 6. We need a mix. What works for kids isn't going to engage retirees who
>>> have been hams from childhood.
>>> 7. Exhibits need to be bulletproof--always working, durable-- especially
>>> self-service ones and browsable displays of artifacts (see #5)
>>> 8. We should consider taking advantage of the devices people carry
>>> around with them.
>>> 9. We need to start at the beginning, as Ernie suggested. Many people,
>>> and not just those under 30, have no idea what electricity is nor much of
>>> anything about how it works, no clear idea about what a radio is or does
>>> (they just expect sound to come out of any box--a radio, a TV, an iPod,
>>> Alexa), no understanding that the driver for almost all the history on the
>>> wireless side of the museum is communication (getting a message from one
>>> place to another) not entertainment, and no awareness of all the codes that
>>> make it possible (Morse code, ...)
>>> 10. We should look for examples to emulate and borrow from, and not only
>>> radio museums. The Exploratorium (https://www.exploratorium.edu/exhibits)
>>> comes to mind. And Spark (https://www.sparkmuseum.org). The best of
>>> them seem to take little bites--exhibits that each try to get an 'aha'
>>> about just one important concept in one small chunk of time.
>>>
>>> Dave
>>>
>>>
>>> On Fri, Aug 23, 2019 at 11:19 PM Ken Carr via Thursday <
>>> thursday at newsm.org> wrote:
>>>
>>>> This post is mostly directed at the NESWM hams.
>>>> Suggestions and comments are welcome from all.
>>>>
>>>> Randy has asked for some suggestions for additional interactive
>>>> (engaging)
>>>> radio-related displays at the museum.
>>>> We already have an excellent start with the interactive displays in the
>>>> wireless building. I believe *Craig* and several other people were
>>>> responsible
>>>> for that (my favorite is the little tubes that light up ... can't
>>>> recall their name).
>>>>
>>>> Below I have a list of some suggested exhibits. One of them, the
>>>> scanning
>>>> disk TV, was suggested by Chris Prata last Wednesday night as we were
>>>> touring the museum with some guests.
>>>>
>>>> The list I came up with is short on particulars and I'm not sure what is
>>>> workable. It is just a bunch of quick ideas.
>>>> It would be good if everyone could come up with a list and we could all
>>>> discuss particulars.
>>>>
>>>> ----------------------------------------------------------------------------------------
>>>>
>>>> *Interactive Radio Displays*
>>>>
>>>>
>>>>
>>>> *Operating an old radio*
>>>>
>>>> Computer station displays photos of a sampling of old radios from NEWS
>>>> collection... Clicking on any radio brings up 3-minute video of that radio
>>>> being operated. Show a little about what was done to revive radio, feature
>>>> period ads from catalogs or museums for this radio, and finally show how to
>>>> operate it. Period accessories should be used (headphones, speaker, meter
>>>> to monitor filament voltage, radio premiums of period, etc.)
>>>>
>>>>
>>>>
>>>> *Can you play this radio?*
>>>>
>>>> Complex looking radio receiver is on small desk with table. Sign no. 1
>>>> with instructions (i.e. 1-5) guide patron to tuning in local broadcast
>>>> station or our own transmission on BC band. Sign no. 2 is “Expert
>>>> Challenge” which steps through process of tuning in live ham radio QSO in
>>>> single side band (SSB). Demonstration includes antique headphones and
>>>> antiseptic wipes.
>>>>
>>>>
>>>>
>>>> *Build a Crystal Radio in 5 Minutes or Less*
>>>>
>>>> Group challenge. Museum guide seats 5 patrons at radio construction
>>>> booths (cubicles) arranged in semicircle. Booths and walls feature photos
>>>> of crystal radios and accessories from our collection along with period
>>>> advertising. Docent gives 5-8 minute talk about crystal radios and
>>>> specifically fox hole radio. Each cubicle has instructions (displayed on
>>>> placard) for constructing radio. Docent passes out parts kit to patrons and
>>>> tells them to begin making a radio. Docent provides guidance if needed.
>>>> Each person’s first name is put on scoreboard with time they took to make
>>>> functional radio. As patrons leave they are given handout that illustrates
>>>> how to make 3 different crystal radios at home: simple, intermediate,
>>>> advanced. Learn More: Web and book references provided at end of handout.
>>>>
>>>>
>>>>
>>>> *Morse Code Challenge*
>>>>
>>>> 1 Watch short video or read simple instructions on placard on how to
>>>> operate code key.
>>>>
>>>> 2 Patron follows instructions and sends message with straight key.
>>>> Message is ‘received’ on computer screen (old iPad running audio to code
>>>> interpretation app). Patron encouraged to persist at keying until message
>>>> is ‘properly received’ (display reflects what patron intended to send).
>>>>
>>>> 3 Advanced Challenge no. 1: Perform as above with sidewinder key.
>>>>
>>>> 4 Advanced Challenge no. 2: Perform as above using antique wireless age
>>>> key and sounder.
>>>>
>>>>
>>>>
>>>> *Antennas* : Make an antenna. Docent demonstrates how radio without
>>>> antenna receives nothing. Then constructs dipole. Next switch in dipole
>>>> that is outside and tune same spot on radio.
>>>>
>>>>
>>>>
>>>> *Or:* Station consists of radio and labeled antenna switch (A, No
>>>> antenna; B. 10 foot wire; C, Outside dipole). Patron switches antennas to
>>>> demonstrate difference.
>>>>
>>>>
>>>>
>>>> *Match The Tubes:* Patron presented with 5 different vacuum tubes from
>>>> different eras (tubes are in a basket or wood block with hollowed out areas
>>>> to receive tubes). Below are five descriptions of each tube in
>>>> chronological order.  Patron must place proper  tube in the slot with the
>>>> matching description.  This encourages  them to read about the different
>>>> tubes and recognize features.
>>>>
>>>> Bonus: If they get the tubes in the correct order they will light up
>>>> and radio station will be heard. To make this work each tube has a stiff
>>>> pin/wire or dowel attached to its central indexing tab. Pins vary in
>>>> length. If all pins are placed correctly each one will activate a relay in
>>>> a string of relays which collectively will turn on the radio.
>>>>
>>>> *Make the Radio Work*;  Circuit diagram of radio is drawn on wooden
>>>> easel. The drawing has actual binding posts and tube sockets. Hidden below
>>>> is a real radio. At each position where a tube belongs there is a real tube
>>>> socket. Flip chart explains how to ‘activate’ the radio:
>>>>
>>>> 1 attach the indoor antenna (patron ties in antenna with alligator clip
>>>> and lead … 10 foot wire antenna)
>>>>
>>>> 2 Insert mixer / converter tube, no. ****** (text briefly explains what
>>>> this does)
>>>>
>>>> 3 Insert First IF tube, no. ******* (text briefly explains what this
>>>> does)
>>>>
>>>> 4 Insert 2nd IF / detector tube no. ******* (text briefly explains
>>>> what this does)
>>>>
>>>> 5 Insert audio amplifier tube no. no. ******* (text briefly explains
>>>> what this does)
>>>>
>>>> 6 Turn on radio (volume/on switch attached to board)
>>>>
>>>> 7 Adjust station with tuner control
>>>>
>>>> 8 Unhook antenna lead and attach to bigger antenna (antenna no. 2, up
>>>> 25 feet outside)
>>>>
>>>>
>>>>
>>>> *Tune a Radio:*
>>>>
>>>>
>>>>
>>>> 1.      Presented with a 1920’s regenerative radio. Instructions show
>>>> how to turn on and tune. Patron does so. Warned about excessive feedback
>>>> and howling. Turn off and go to second radio.
>>>>
>>>> 2.      Presented with a 1920’s 3-dialer (Tuned Radio Frequency)
>>>> radio. Proceed as above
>>>>
>>>> 3.      Presented with a 1940’s superheterodyne console radio.
>>>> Instructions show how to turn on, tune station, and turn off.
>>>>
>>>> At each stage patron is informed about merits and faults of each design.
>>>>
>>>>
>>>>
>>>> *Do You Cohere?*
>>>>
>>>> Station has several coherers that work on different principles.
>>>>
>>>> Patron is briefly informed of function of coherer and is then
>>>> encouraged to make each one work.
>>>>
>>>> 1.      Patron dials up power on rheostat and then presses code key
>>>> (massive) and sends ‘spark wireless radio transmission’ (actually a nearby
>>>> but hidden transmitter is activated).
>>>>
>>>> Audio creates sound of spark transmission. As rheostat voltage is
>>>> increased more of the coherers activate , thus demonstrating the relative
>>>> sensitivity of each design.
>>>>
>>>> Coherers begin to cohere and as they do a sounder next to each is
>>>> activated just once.
>>>>
>>>> 2.      Next the theory of the decoherer is explained and patron
>>>> performs same task as above but with set of coherers that include
>>>> decoherers. Constant buzz with interruptions (long and short Morse code
>>>> characters) is heard. Communication is now possible.
>>>>
>>>> *Amplify This !*
>>>>
>>>> Patron is presented with working crystal radio. It is explained that
>>>> since they work on very little current (whatever is present in the radio
>>>> wave itself) it is not enough to make loud noise. How might they make it
>>>> louder (amplify)?
>>>>
>>>> Solution no. 1  Attach two sets of earphones to one crystal radio so
>>>> more than one person can listen in. Unfortunately with the addition of each
>>>> earphone the volume in each is reduced.
>>>>
>>>> Solution no. 2 Make the output of the earphone reverberate against the
>>>> walls of an expanding horn. Connect earphone to the end of a horn speaker. *(Randy's
>>>> idea)*
>>>>
>>>> Solution no. 3 Attach output of crystal radio to a crude amplifier. We
>>>> may build one or better still attach the crystal receiver to the kind of
>>>> amplifier that was sold as an accessory to the Radiola III (we have at
>>>> least one of these on display in the museum. I suspect more are squirreled
>>>> away somewhere). Other solutions are offered in various crystal radio
>>>> enthusiast books. We can also provide tube and transistor-based amplifiers
>>>> that can be switched in from a control panel.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> *Create Electronic Components From Scratch*
>>>>
>>>> Patron presented with samples of production electronic / radio
>>>> components. Each is explained and its operation in a circuit is
>>>> demonstrated (connect to circuit, push button to activate, effect seen on
>>>> attached meter, lamp, speaker, etc.)
>>>>
>>>> Next patron is given material to ‘make’ their own components. They then
>>>> test them by inserting into circuits. Resistors and capacitors may be taken
>>>> home. Printed labels provided for outside of capacitors and resistors.
>>>>
>>>> Everything is run on battery power, no high voltage danger.
>>>>
>>>> Components: Resistor, Capacitor, transformer
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> *Mechanical Television Camera*
>>>>
>>>> Mechanical television camera is activated by patron and image of patron
>>>> is seen on vintage TV (round porthole style) CRT. *(Chris Prata)*
>>>>
>>>>
>>>>
>>>> *Library*
>>>>
>>>> Open the library for study by anyone. Although we will not lend
>>>> publications, patrons are free to purchase photocopies of select pages of
>>>> old publications. We make the copies and charge 50 cents per page (or
>>>> whatever fee schedule that gives us some revenue and keeps the patrons
>>>> happy). The library can have rotating theme displays that feature such
>>>> items as: original patents, advertising illustrations, collections that
>>>> address one particular field, etc.
>>>>
>>>> Posters that are reproductions of illustrations might be on sale in the
>>>> library.
>>>>
>>>>
>>>>
>>>> *Radio Drama Room (Old Time Radio)*
>>>>
>>>> Small groups (5-20 at a time) enter our ‘living room’ which is set up
>>>> like a living room from 1939. There is a large console radio with a tuning
>>>> eye, a rug on the floor, upholstered couches and chairs, etc. Make it look
>>>> just like 1939 … real comfy. When everyone is seated the radio comes on (a
>>>> child patron is asked to do the honors). The lights dim and the only bright
>>>> light in the room comes from the radio. An announcer comes on and does the
>>>> intro for today’s show.
>>>>
>>>> It may be The Shadow, Buns and Allen, Johnny Dollar, Jack Benny, etc.
>>>> Choose titles that are appropriate to the season (horror during the fall,
>>>> Christmas shows in December, etc.). The show will run for about 20-30
>>>> minutes. The room should be well ventilated (AC) and sound proof.
>>>>
>>>>
>>>>
>>>> *Make a radio transmitter in 5 seconds*
>>>>
>>>> Display radio is tuned to portion of the band that does not have a
>>>> station playing. The patron is given several items with which they may
>>>> create electric discharges through the rubbing together of dissimilar
>>>> materials. If the humidity is correct (low humidity, dry weather; AC will
>>>> help) they will hear the discharge on the radio. Placard explains that this
>>>> was the basis for early spark transmitters. Note that the emission can be
>>>> heard anywhere on the band. This would never work for broadcast radio.
>>>> Eventually radio transmitters that used vacuum tubes and finely ‘tuned’
>>>> circuits were able to create distinct ‘radio stations’ on specific
>>>> frequencies.
>>>>
>>>>
>>>>
>>>> *How is your Radio Eyesight?*
>>>>
>>>> Present patron with an operating radio that has a tuning eye (magic
>>>> eye, miniature cathode ray tube). Explain the theory of how it works.
>>>> Encourage patron to ‘tune’ the radio to various stations using the tuning
>>>> eye for accuracy.  If possible lighting should be subdued at this exhibit.
>>>> Point out how the eye opening varies with signal strength.
>>>>
>>>>
>>>>
>>>> *How do you put a value on an antique radio?*
>>>>
>>>> Display 6—10  antique radios and speakers. They are in various states
>>>> of repair and completeness. Provide overall guide as to what features
>>>> determine the value of a particular radio. This can be text that is
>>>> displayed above the radios or it may be audio that can be accessed with
>>>> earphones (disinfected earphones like those in airplanes are given to all
>>>> patrons with admission ticket).
>>>>
>>>> After listening to the audio discussion on radio values the patron uses
>>>> a  ‘score card’ that is keyed to the display radios. They must grade each
>>>> radio on certain characteristics and finally put a dollar value on the
>>>> radio (pencils available). When they have completed the score card they
>>>> press an ‘answer’ button that reveals the values and explains why each
>>>> radio has a particular value to collectors.
>>>>
>>>> *Radios of Rhode Island*
>>>>
>>>> Special exhibit put together by *Len A.*
>>>>
>>>> *How is a radio restored?*
>>>>
>>>> Static exhibit of about 5 models of the same radio, each showing the
>>>> progression of steps involved in restoring that radio.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> *Interactive Analogue Demonstration of Stages of Superheterodyne Radio
>>>> Receiver*
>>>>
>>>> Most explanations of how a simple superheterodyne radio works are too
>>>> complex or vague to keep a person’s interest or to convey understanding. If
>>>> each electronic stage of the superheterodyne radio is displayed alongside a
>>>> working mechanical (not electronic) analogue of the separate stages it may
>>>> be possible to illustrate how a radio works in an intelligible manner.
>>>>
>>>> The setup:
>>>>
>>>> Front and center (controllable and accessible to the patron) are 6
>>>> working devices that convey each successive stage of a radio receiver. None
>>>> of these devices are electronic or necessarily electric. They demonstrate
>>>> physical properties or observed mechanical phenomena that are similar
>>>> (analogous) to the electrical or electromagnetic functions of each stage of
>>>> a radio receiver. Some examples (not necessarily accurate):
>>>>
>>>> Tuning forks and multiple piano strings: fan dipole antenna as a medium
>>>> that electronic vibrations (radio waves)  pass through and vibrate within,
>>>> some better than others, due to ratio of antenna length to waveform length.
>>>> (Represent antenna by fan dipole).
>>>>
>>>> Structure consisting of mass suspended by springs and set in motion by
>>>> eccentric drive which reaches maximum amplitude when spring-capacitor and
>>>> mass-inductor are in phase or what would be called resonance in radio
>>>> circuit. (p. 444, Sutton, Electrical Oscillations). This mimics the local
>>>> oscillator of the radio.
>>>>
>>>> Competing waveforms may when they collide result in addition and new
>>>> (sum) waveform is produced as demonstrated in rod model (p. 139, S-28,
>>>> Sutton (1937). This is analogous to the mixer stage of radio although in a
>>>> radio sum and subtraction of RF is produced. The difference is the
>>>> frequency that is selected out. This mimics the mixer section of the radio.
>>>> (Note: the mixer and local oscillator are usually combined in one vacuum
>>>> tube and together referred to as the converter stage.
>>>>
>>>> The output of the converter / mixer is fed to the Intermediate
>>>> Frequency stage which is a circuit tuned to a particular frequency. It has
>>>> an amplifier (tube) that is optimized to amplify only that one frequency,
>>>> the intermediate frequency, which is allowed to pass through this stage and
>>>> pass to the vacuum tube for amplification. Analogue representation of this
>>>> stage: 4 different tuning forks are tapped. In front of them is one piano
>>>> wire. It only responds (vibrates/ oscillates) in response to one of the
>>>> four tuning forks since its length allows it to vibrate optimally at just
>>>> one frequency.
>>>>
>>>> And so on through the remaining stages of the radio.
>>>>
>>>> Behind the Mechanical models is a large labeled and color coded block
>>>> diagram of a radio.
>>>>
>>>> Rather than a block diagram you might use actual radio parts within the
>>>> blocks.
>>>>
>>>> Activating any physical model will cause the analogous radio stage to
>>>> light up. Where appropriate actual radio tubes (with clear designations in
>>>> front of each) can be used. Safe DC battery power would be applied to
>>>> filaments only as each stage is selected.
>>>>
>>>> Finally patron will be encouraged to turn on the ‘radio’ and tune in a
>>>> station. 5-part fan dipole has numerous colors (frequencies along its
>>>> length). Only one color at a time appears in ‘glow’ of the converter stage.
>>>> Local oscillator (LO) within converter stage has a different color. The
>>>> color that emerges from this stage and goes to IF amplifier is always the
>>>> same color as the LO (others are filtered out). As tuning dial is rotated
>>>> you see that the color entering the converter stage change, one color for
>>>> each station frequency.
>>>>
>>>> And more stages follow …….
>>>>
>>>> This display could have several things that the patron could control. A
>>>> lot of planning would need to go into this. It would be good for an
>>>> electrical engineer to supervise the design.
>>>> *Comments and additional ideas welcome*.
>>>>
>>>> ------------------------------
>>>>
>>>> *Ken Carr* ...
>>>> KE1RI, A New England Ham <http://www.idlenot.com>
>>>> Westerly-Pawcatuck AACA <http://www.wpraaca.com>
>>>> N.E. Steam & Wireless Museum <https://www.newsm.org>
>>>>
>>>>
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>>>>
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>>
>>
>> --
>> Randy Snow
>>
>> Snow Findings Company <http://www.snowfindings.com>
>> Lovements.com <http://www.lovements.com>
>> New England Wireless and Steam Museum <http://www.newsm.org>
>>
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>
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