referring to fig3 and 4 , the inventive radiated field detector 52 is configured to detect an electromagnetic field generated by a solid - state device 50 , such as an electronic igniter , which is used with either an intermittent pilot flame or which ignites a burner directly with a spark . the igniter 50 would not function unless the transformer functions and generates sufficient voltage . the radiated field detector device 52 includes a housing 54 typically made from light material , which may include plastic or metal , and enclosing detecting circuit that may be implemented in a variety of ways . principally , as better illustrated in fig4 , the detector device 52 has a radiated field pick - up means , such as an antenna 56 , generating an antenna current in response to the rf radiation that is emitted by the operating transformer or upon generating a spark and is incident on the antenna 56 . the antenna current is amplified by an amplifier 58 to a desired output signal sufficient to provide voltage differential across an indicator means 60 , which can visually signal the presence of the sensed radiated field and , thus , the operating state of the igniter 50 . additionally , an audio circuit can be added to produce an audio signal along with the visual signal . in use , the detector device 52 can be placed either directly on the solid - state device 50 , as shown in fig3 , or a support located in the vicinity of the solid - state device 50 at a distance up to several inches , and left untouched by the operator . accordingly , the risk of exposing the operator to high voltage is completely eliminated . if the igniter functions properly — either a spark is generated or a transformer functions properly — a flashing light signal , lasting for a few seconds , and / or an audio signal will attract the operator / repairman &# 39 ; s attention . if the signal is not generated , after the operator inspects and determines that the electrical connections are sound , the igniter is automatically identified as the cause of the problem , associated either with the capacitor or the transformer , and should be replaced . an example of a light - indication high - impedance circuitry configured in accordance with the invention to sense or monitor the radiated field is illustrated in fig5 . in operation , the antenna 56 is inductively coupled to the transformer of the solid - state device 50 , typically radiating electromagnetic energy in a high - frequency range , to output ac antenna current , which is typically small . after rectification performed by a pair of diodes 62 shunting the negative portion of the sinusoid waveform to ground , the positive portion will charge up a capacitor ( c 1 ) 64 to 8v , which acts as a power supply source for a load including a transistor 66 and a resistor r 5 . since the antenna current is low , to activate the transistor 66 , it is preferred to use a darlington set - up in which two regular transistors are ganged . the use of the darlington set - up for the purposes of proper functioning of the circuitry is not exclusive . for example , a fet can be utilized as well . however , while the darlington transistor can be activated by as low a power as a 4v source , typically the fet requires a more powerful source . by properly selecting resistors r 6 and r 2 , the circuitry is able to provide a voltage sufficient to turn on an scr or thyristor 68 connected in series with the indicator 60 , such as an led . once a voltage of about 2v is achieved , the thyristor 68 is triggered or closed and , thus , the voltage differential across the indicator 60 is achieved to cause the latter to go on and off for a few - second reporting time period during the bleeding period of the capacitor 64 . in addition , the inventive testing device 52 can operate in a self - test mode . for this purpose , in response to pushing a rocker switch 70 ( fig3 ) connecting a power source , such as a 9 v battery , the led 60 should blink indicating that the testing device 52 is in a good operating condition . otherwise , the testing device is to be inspected and , if the battery is not the cause of the problem , replaced . to facilitate mounting of the inventive device 52 either directly on the solid - state transformer / igniter 50 or on any other support located in the vicinity of the igniter 50 , the housing 54 of the inventive device 52 can be provided with a mounting means including a plurality of suction cups 76 ( fig3 ) and / or hooks ( not shown ). to generate a sound signal , a standard sound - generating circuit can be integrally provided within the housing 54 of the testing / monitoring device 52 . it is conceived to provide a kit including the inventive testing device along with a variety of mounting means . although the inventive device has been disclosed in the high - frequency range context , a skilled worker can easily use the device as a tester of a radiated low frequency field . as such , for example , the device can be a reliable indicator of properly functioning transformer , provided , of course , it is properly positioned . in this case , the antenna would function as a simple pick - up coil . accordingly , while the invention has been disclosed with respect to preferred embodiments , various changes can be made without departing from the scope of the invention as defined by the appended claims .