8

Assuming that you're operating in the jurisdiction of the FCC, there should be no legal issue with you modifying your radio and using it to transmit on those two bands providing the following: Your modifications comply with good engineering practice, and You do not exceed the privileges (power or frequency) of your license Unlike other radio services in ...


5

So, you say: I don't care if the signals are delayed. I'm just tapping the line out to a pan adapter. I am most concerned about influencing the existing function of the receiver And that's exactly what you're going to do with this. Your Opamp circuit has a high impedance, which translates into "looks like an open end". That means that your tapping coax ...


5

Using this site, I determined the operating range is: FM: 87.5 - 108 MHz, AM: 526.5 - 1606.5 KHz The closest ham bands are 144-148 MHz, 1800-2000 kHz. Thus, it cannot receive ham bands without modification. With modification, essentially you need to open the radio and re-tune it's frequency calibration. There is a website that documents how to do this. ...


4

My answer It looks to me like you could probably go further outside the limits of the band you're switched to by using an external VFO with a wider tuning range than the inbuilt LMO (5.0 to 5.5 MHz) but the pass-band tuned circuits will limit the amount you can do this by. I'm fairly sure the WARC bands would be too far away from the original fitted bands ...


3

Yes, attaching a general-purpose frequency counter to the local oscillator of a superheterodyne radio will result in displaying a frequency with an offset either above or below (depending on the design of the radio) the nominal frequency of the signal being received. In order to account for this, apply the reverse offset numerically, between the frequency ...


3

First, consider how the circuit works. It's a Wheatstone bridge, although you might have to squint and turn your head to see it. Think about how "Tune" is a connection to ground through what should be a 50 ohm impedance. Here it is redrawn a bit: simulate this circuit – Schematic created using CircuitLab When the antenna is tuned, then R2 and R3 make ...


2

No. You likely would need to build two new transmit stages and rewrite the firmware. Each transmit stage uses a precise final oscillator and mixer which is specific to the frequency band as well as a filter to suppress harmonics, use of the hardware for 70cm at a 33cm frequency would result in most of your transmit signal being filtered out - if it was even ...


2

An optoisolator would not likely accomplish what you're wanting here (relatively low feed impedance, with not-so-great linearity). Op Amps seem to be the generally preferred implimentation for buffer amps now; something like this should work for you: Alternately, if you don't want to directly connect anything to your IF line, you could use a close-coupled ...


2

Can I turn on every GPS, WIFI and Bluetooth radio of a mobile device and synchronize data transfers at extreme speeds between a small, short-range network of devices? This question has several parts. "Which radios in a typical mobile device can both transmit and receive?" Typically they'll have Wifi, Bluetooth, CDMA/GSM, and LTE for recent devices. The ...


1

I doubt such a device will ever exist, I'm afraid. The problem is the TNC-radio interface. Packet at 1200 bps is pretty forgiving, you can hold your radio up to a computer or phone's speaker or mic and it'll work, more or less. Packet at 9600 bps, on the other hand, requires a connection deeper inside the radio because there is circuitry (or nowadays, ...


1

As long as the fan is a 12V fan you can use one of a number of solutions computer building enthusiasts use to control their case fans. One which might work for you is the following device: http://www.frozencpu.com/products/5301/tmp-33/NoiseMagic_ThemoControl_NMT-2_Solder_Version.html?tl=g47c17 This takes a 12V input, controls a 12V fan, and can be ...


1

No. Even if you modified it to tune amateur radio frequencies, it won't receive the modulation schemes used. Broadcast FM is wideband FM, which is not legal for amateurs on most frequencies. AM is legal for amateurs, but only rarely used. Shortwave receivers that support SSB reception usually work for monitoring shortwave (HF) amateur radio transmissions. ...


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