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Ham bands only rigs, off-band operation?
On May 7, 9:13 pm, (Michael Black) wrote:
"Rick " ) writes: Typically, can ham-bands-only receivers such as the Drake R4 and Collins 75A or 75S series, transmitters such as the Collins 32S and Drake T4 series, and transceivers such as Drake TR-4 and Collins KWM-2, be modified to work on CAP and MARS frequencies? I know that some radios have provisions for installing crystals so that they'll work on off-band frequencies. How can I determine which radios are modifiable that way, and also where is a good place to get crystals these days? CAP and MARS frequencies were (I don't know if it's the case now) generally chosen to be adjacent to ham bands so ham equipment could be used. There's little sense of having an auxiliary if the operators have to buy extra equipment or the organization has to do so. Remember, they date from before the new fangled equipment came along. Transmitters were easy, just pop in a suitable crystal and the rest of the unit would have enough leeway to tune the adjacent frequency. Receivers were more of a problem, since retuning generally meant retuning the local oscillator, there weren't always crystals to select the range. But a receiver that had a bit of overlap was usually okay. Hence, most equipment would be modifiable, if there wasn't enough overlap. Michael VE2BVW Collins S-Line (which includes KWM-2) is not strictly "ham band only" in the normal sense of the word. There are 15 or 30 selectable crystal positions which give a 200 kHz swing in the ranges of 3.4-5.0 and 6.5-30.0 MHz. It's possible to use an external frequency reference to hit a "dead nuts on" transmit frequency but for normal use you only have to be within a designated band limit. There was a crystal accessory originally intended for Novice ham use when they were rockbound. Use a counter or service monitor to check your transmit frequency if you are worried, but I doubt MARS or CAP is going to care if you are 1 khz or less off. Come to think of it, what are CAP's HF allocaions anyway? |
#2
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Ham bands only rigs, off-band operation?
"RapidRonnie" wrote in message ps.com... On May 7, 9:13 pm, (Michael Black) wrote: "Rick " ) writes: Typically, can ham-bands-only receivers such as the Drake R4 and Collins 75A or 75S series, transmitters such as the Collins 32S and Drake T4 series, and transceivers such as Drake TR-4 and Collins KWM-2, be modified to work on CAP and MARS frequencies? I know that some radios have provisions for installing crystals so that they'll work on off-band frequencies. How can I determine which radios are modifiable that way, and also where is a good place to get crystals these days? CAP and MARS frequencies were (I don't know if it's the case now) generally chosen to be adjacent to ham bands so ham equipment could be used. There's little sense of having an auxiliary if the operators have to buy extra equipment or the organization has to do so. Remember, they date from before the new fangled equipment came along. Transmitters were easy, just pop in a suitable crystal and the rest of the unit would have enough leeway to tune the adjacent frequency. Receivers were more of a problem, since retuning generally meant retuning the local oscillator, there weren't always crystals to select the range. But a receiver that had a bit of overlap was usually okay. Hence, most equipment would be modifiable, if there wasn't enough overlap. Michael VE2BVW Collins S-Line (which includes KWM-2) is not strictly "ham band only" in the normal sense of the word. There are 15 or 30 selectable crystal positions which give a 200 kHz swing in the ranges of 3.4-5.0 and 6.5-30.0 MHz. It's possible to use an external frequency reference to hit a "dead nuts on" transmit frequency but for normal use you only have to be within a designated band limit. There was a crystal accessory originally intended for Novice ham use when they were rockbound. Use a counter or service monitor to check your transmit frequency if you are worried, but I doubt MARS or CAP is going to care if you are 1 khz or less off. Come to think of it, what are CAP's HF allocaions anyway? CAP members, like MARs, are instructed not to reveal any frequency allocations due to OPSEC. J |
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Ham bands only rigs, off-band operation?
On May 8, 11:26 pm, "Jerry" wrote:
"RapidRonnie" wrote in message ps.com... On May 7, 9:13 pm, (Michael Black) wrote: "Rick " ) writes: Typically, can ham-bands-only receivers such as the Drake R4 and Collins 75A or 75S series, transmitters such as the Collins 32S and Drake T4 series, and transceivers such as Drake TR-4 and Collins KWM-2, be modified to work on CAP and MARS frequencies? I know that some radios have provisions for installing crystals so that they'll work on off-band frequencies. How can I determine which radios are modifiable that way, and also where is a good place to get crystals these days? CAP and MARS frequencies were (I don't know if it's the case now) generally chosen to be adjacent to ham bands so ham equipment could be used. There's little sense of having an auxiliary if the operators have to buy extra equipment or the organization has to do so. Remember, they date from before the new fangled equipment came along. Transmitters were easy, just pop in a suitable crystal and the rest of the unit would have enough leeway to tune the adjacent frequency. Receivers were more of a problem, since retuning generally meant retuning the local oscillator, there weren't always crystals to select the range. But a receiver that had a bit of overlap was usually okay. Hence, most equipment would be modifiable, if there wasn't enough overlap. Michael VE2BVW Collins S-Line (which includes KWM-2) is not strictly "ham band only" in the normal sense of the word. There are 15 or 30 selectable crystal positions which give a 200 kHz swing in the ranges of 3.4-5.0 and 6.5-30.0 MHz. It's possible to use an external frequency reference to hit a "dead nuts on" transmit frequency but for normal use you only have to be within a designated band limit. There was a crystal accessory originally intended for Novice ham use when they were rockbound. Use a counter or service monitor to check your transmit frequency if you are worried, but I doubt MARS or CAP is going to care if you are 1 khz or less off. Come to think of it, what are CAP's HF allocaions anyway? You are full of ****!!!!!! CAP is civil search and rescue. MARS is military AFFILIATE-not operational. Full of ****. Just for that I'll monitor and post a couple. |
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