Understanding the 60 meter band channels (Part 1)
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- Опубліковано 4 жов 2020
- Allowing amateur operators use of the 60-meter band was fiercely opposed by the National Telecommunications and Information Administration (NTIA). The ARRL argued that the 60m band could bridge a much-needed gap for use by amateur radio operators involved in emergency communications, when 80m is too short and 40m is too long. The FCC went to the mat for the amateur radio community and fought the NTIA until they agreed to share 5 lightly used areas of spectrum with the amateur radio community. The NTIA considered each of these 5 portions of spectrum as channels. But the agreement required the amateur operators not to exceed 2.8 kHz of transmit bandwidth. So, when we modify an older radio to operate on the 60m band, we must be mindful of our TX bandwidth.
I will attempt to clear up the confusion concerning the 60-meter band. Channel 1 of 60 meters has a center frequency of 5332 kHz, or 5.332 MHz. That means that our 2.8 kHz of TX bandwidth must fall within +/- 1.4 kHz of bandwidth. For example, our transmit audio on Channel 1 USB must not extend beyond 5.3334 MHz. If we transmit using upper sideband modulation, on the center frequency of the channel, 5.332 MHz, with a 2.8 kHz TX bandwidth, we will be 1.4 kHz beyond our channel slot. Above and below our 2.8 kHz of allowed bandwidth are portions of the spectrum that are allocated for government use. We cannot, and must not, transmit in these portions of the 5 MHz band.
If this still seems confusing, let’s consider one of the questions on the amateur radio exams. On the 20-meter band, the maximum frequency we can set our VFO to is 14.347 MHz, when using USB. The VFO display is indicating where our suppressed carrier will be centered. Furthermore, the lower sideband will be suppressed. When we transmit, our 2.8 kHz wide upper sideband modulation won’t extend beyond 14.350 MHz. Though your radio might be able to transmit with a bandwidth of 3 kHz, setting the TX bandwidth to 2.8 kHz helps ensure that your modulated signal doesn’t extend beyond the band edge. Many radios from the past shipped with a default TX bandwidth of 2.8 kHz. That is a reasonable bandwidth that yields good quality TX audio.
Now let’s apply all of this background to 60 meters. The official center frequency of channel 1 is 5.332 MHz (5332 kHz). Now, assume that you have an older radio and you have performed the MARS modification to the radio, so you can transmit on 5 MHz. As a bonus, you’re going to assign the ten 60-meter channels to memory positions in your older radio, to mimic how newer radios include pre-programmed 60-meter channels. In order for your 2.8 kHz wide upper sideband modulation not to extend beyond 5.3334 MHz, you must set your suppressed carrier frequency 1.4 kHz below the designated center frequency of the channel. But alas, you actually set the suppressed carrier frequency, as displayed on your radio, to 1.5 kHz below the center of the channel. I know it seems confusing, because we are told that the entire channel must be only 2.8 kHz wide, not 3 kHz. But the FCC appears to be allotting us 3 kHz of bandwidth. We should still keep our TX bandwidth at 2.8 kHz to ensure that we don’t inadvertently exceed our limits on the 60-meter channels.
I hope this video helps clear some of the confusion associated with the 60-meter band.
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73, de N4HNH - Наука та технологія
Amazing! You answered my initial question and also explained this band in much greater detail than I realized even needed answering. There are very few videos about 60 meters and I'm sure a lot of people will appreciate this series on the topic.
Thank you! I hope this helps unravel some of the mystery related to 60 meters. 73, Doug
The following comment explains why the FCC (as discussed beginning at 10:44) allows the suppressed carrier frequency to be set 1.5 kHz below the channel's center frequency rather than 1.4 kHz. An audio tone at frequency f transmitted via upper sideband with respect to suppressed carrier frequency F' will produce an output at frequency F'+f. An amateur transmitter is deliberately not "high fidelity" and has negligible audio response for frequencies less than 100 Hz and above 2900 Hz. That means that if an audio frequency f lies between 100 Hz and 2900 Hz, then the transmitted signal will have a frequency between F'+100 Hz and F'+2900 Hz. If F' is set to F - 1.5 kHz, where F is the channel's center frequency, then the transmitted frequency range will be F - 1.4 kHz to F + 1.4 kHz, giving a 2.8 kHz bandwidth around the channel's center frequency F.
That’s good to know. I didn’t know the FCC thought it through like that. Yaesu limits the TX bandwidth to 2.8 on their programmed 60m channels. I guess if someone performed a Mars mod and used eSSB , that could cause an issue.
Just give the freqs pls? I need the time, not how to build a clock…
@Nimbus495 the frequencies are all over the web. Use Google. This 3-part video series is about the nuts and bolts of why the band is set up by channels. It’s also about staying legal on a band we share with government entities. And I do show the frequencies for the USA in this series.
@@Nimbus495 From the ARRL, the five 60 m channels, marking the center of upper-sideband transmission, are: 5330.5, 5346.5, 5357.0, 5371.5, and 5403.5 kHz. These frequencies are available for use only by stations having a control operator holding a General, Advanced or Amateur Extra class license (not Technician).
This is the best and foremost teaching I've found on UA-cam ( about this subject). I've become more skilled and a better operator as a result of this video. Thank you Tremendously. I've learned a lot from your channel over my short tenure as a HAm. Thank goodness you like Yaesu Radios!!! 73 DE K4KHO
Thank you for your encouraging words. It is my goal to help others get more enjoyment from their radio equipment.
73, de N4HNH
I think I read somewhere that when using CW on the 60m band, you need to transmit right on the center frequency.
You didn’t mention this here.. but perhaps you will in Part 2. Thanks a ton.
Mike - KK7MMN
Unless you modify the FT-891, it automatically transmits at the center of the channel for CW. It also automatically transmits 1.5kHz below the channel center when using the USB channels.
Clear as mud
60 meters is an odd band. I hope by the time you have watched part 3 it will make more sense. It’s similar to CB radio, but there are only 5 channels instead of 40.
We can use either CW, at the center of the channel, or USB, at 1.5kHz below the center of the channel. A Yaesu radios is programmed for you so it transmits at the correct frequency within the channel. Just use one of the frequencies in memory bank 5.
73, de N4HNH
So, the radio is transmitting and receiving 1.4 below the channel center even though it displays the channel center frequency?
The radio transmits 1.5kHz below the center of the channel, as displayed on the screen. For CW mode, the radio transmits at the center of the channel, as displayed. Yaesu also programmed in the 2.8kHz maximum TX audio bandwidth.
@@n4hnhradio Thanks. I get that but what freq is the radio receiving on? 1.5kHz below the channel center? So if I was setting this all up manually i would tune my radio 1.5kHz below the channel center for SSB. Seems like a convoluted way of doing things.
@w4mkh Have you watched all three videos? There is a 3kHz width for each channel. For CW, we transmit in the middle of the channel. For USB, we transmit and receive at 1.5kHz below the channel center. Think of it as the bottom edge of the channel. Since it’s a 3kHz window, our 2.8kHz maximum TX audio stays within the channel. We are sharing with the government. So it’s convoluted for a reason. They didn’t want us to have it. So we must play nice and stay at 100W ERP or lower.
If you set this up yourself, on a radio that allows it, you will need to enter the USB frequencies per the frequencies I show in the series.
@@n4hnhradio Got it. Thanks.
Don't forget that CB can use both usb and lsb, I know but I still love CB lol
Indeed! And CB is also channelized. I love how the marketing brochures used to say a CB has 120 channels. 40AM, 40LSB, and 40USB. 73
60 meters is more bull s_ _ _ than it's worth.
This is the best and foremost teaching I've found on UA-cam ( about this subject). I've become more skilled and a better operator as a result of this video. Thank you Tremendously. I've learned a lot from your channel over my short tenure as a HAm. Thank goodness you like Yaesu Radios!!! 73 DE K4KHO
There is no perfect radio but Yaesu gets very close. I find that the manuals are lacking in the area of practical application, thus many people miss out on fully utilizing the capabilities of whichever transceiver they have.
73, de N4HNH