Print This Page
Customers most agreed on the following attributes:
from Latrobe Pa. on 4/10/2008
I used this product inline with a mixer that was having a ground loop problem. It fixed it up and been great ever sense. It maybe bandwidth challanged but then it is not a $200.00 Jensen either. I use it for vocal work only. and i have not seen any distoration in the vocal range at all. I really can not think of a bad thing to say about it.
[3 of 3 customers found this review helpful]
from Windham, NH on 11/9/2007
I used a pair of these to connect the line in of my computer to the speaker wiring in my house without creating a ground loop that would cause hum. With a few added resistors, they worked well for this purpose. The specs listed for this part are, like most Radio Shack parts, incomplete. A transformer?s frequency response is a function of signal amplitude and acceptable flatness of response. In this case, the high frequency response is very conservative and the parts I had easily handle more than 20KHz with no problem. The low frequency response is a function of signal amplitude and is primarily limited by saturation of the core, which causes gross distortion. As you decrease the frequency of the driving signal, the amplitude at which the core will saturate also decreases. For line level signals I think the 300Hz low frequency spec. is also reasonably conservative for audio applications if the frequency content below that frequency is also at a relatively low amplitude.
Others have noted that the primary and secondary are not labeled. Measuring the resistance of the windings, the white and black are the primary and the red and yellow are the secondary. Does it matter? It wouldn?t if they both had the same resistance, but they don?t. In most applications it would make sense to use the lower resistance winding as the primary.
Other specs that are missing are the inter-winding capacitance, the maximum voltage difference between the two windings before they break down and the relative polarities of the primary and secondary connections. The winding polarity is usually denoted by dots on the primary and secondary symbols in the spec to indicate which leads have the same relative phase. In this case, the white and yellow go together. I didn?t measure the inter-winding capacitance or the maximum voltage, but, based on the construction of the transformer, I am guessing it is not designed for high voltage isolation . Although there appears to be a winding on one side of the core and another winding on the other, these are not the primary and secondary. Both are wound on each side so it appears to have been designed to favor good coupling over high isolation.
I measured the frequency response and phase shift. This part is practically perfect; the given frequency range is conservative and could be pushed further. Fantastic isolation transformer.
This little beauty is the heart of a 9v to 700v DC to DC converter I built. It works so well I bought several. The tiny size is perfect for keeping critical dimensions small.
Someone complained about the frequencey response. This is advertised for telephone applications. Telephone systems only use 300Hz-3KHz anyway... Perfect device (for all intents and purposes)
300Hz for an audio isolator is way too high. There is severe distortion. Just waste of money.
Someone complained about the input and output not being identified. This is a 1:1 transformer so it makes no difference! My application is to reduce 60 Hz hum on the input to a soundcard and it has been working perfectly for years.
The transformer seemed to work as advertised but the primary and secondary coils were not identified as they should have been.