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Icom V-8000 Great 2M. rig

Discussion in 'Ham Radio Discussions' started by AB8RU, Jun 11, 2004.

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  1. AB8RU

    AB8RU Ham Member QRZ Page

    Hi everyone, I was at the Hudsonville IRA Hamfest and looked at a couple rigs and decided that I wanted a new 2M. So I settled on the Icom V-8000 , well I got more than I bargained for, full CTCSS, 4 power levels 5, 10, 25, & 75 W. output, controls on the mic, turbo scan, 207 Channels, wow !

    I installed it in my car that afternoon, the cable was heavier gauge than my old rig, a cooling fan multi speed, and much more, I called to a few friends and chatted simplex to the Pres of IRA tonight at the Grocery Store and he was S. of the Main Repeater site, we chatted and he made a good comment how well it worked, everyone said excellent audio.

    If you are shopping for a new rig I would reccommend the Icom V-8000 for a Great Monobander, I thought of going Dual-Band, but I wanted to wait.
     
  2. KJ5T

    KJ5T Premium Subscriber QRZ Page

    I know I guy who got the V8000 aswell, and it he says it is well worth the money.. I mean 75watts is a big difference Vs. 50watts, and he can hit repeaters mobile that are 80 miles from him. It would be a great rig for base aswell I am sure..

    +Steve,KD5OWO
     
  3. K9STH

    K9STH Ham Member QRZ Page

    OWO:

    Actually, in the "real world" the difference between 50 watts and 75 watts is virtually unmeasurable except with a wattmeter located at the transmitting end!

    Where repeaters are involved, once "full quieting" is achieved into the receiver, any more power will not achieve any better signal! The amount of noise on the signal into the repeater is what makes the difference. One the noise is eliminated, any further signal level will have no effect!

    FM is not like AM (and SSB is an AM mode!). With AM the stronger the signal the more audio is produced. That is why AVC or AGC is usually employed to keep the speaker audio level more constant. On FM the "loudness" of the signal is dependent on the deviation (how far the modulated signal goes on either side of the carrier frequency) versus the bandwidth of the receiver filter. As the maximum bandwidth of the filter is approached, the louder the signal sounds. Then, when the bandwidth of the transmitted signal exceeds the bandwidth of the filter, then the audio starts "chopping out" until the transmitted signal gets so wide that no audio is detected at all.

    The noise that is received becomes reduced as the signal level increases. Then, when most of this noise is eliminated (when the ear cannot hear any more noise) then any additional signal level will not increase the intelligibility of the signal one iota! More signal doesn't usually decrease the intelligibility (unless the transmitter is so close to the receiver to actually "overload" the "front end" which happens rarely). Since most FM stations are mobile or portable, once "full quieting" has been achieved, the variations in signal level due to the movement of the station through various terrain will often not result in any loss of intelligibility because the threshold of the signal is not reduced below the "full quieting" point.

    I would bet that the fellow who is using the 75 watt radio could hit the repeater 80 miles away with 50 watts just about as well, if not as well. The antenna that he is using on his mobile as well as the actual location at the time will make a much greater difference than 50 percent more power, especially once the 30 to 50 watt level has been reached.

    Theoretically, the doubling of the power of the transmitter should increase the range by 41 percent (the square root of 2 is 1.414 and theoretical range can be explained by the root mean square rule). However, in practice, doubling the power on an FM transmitter seldom results in an increased range of more than a few percentage points (up to about 10 percent maximum).

    Now, running more power does seem to help "fill in" some areas that were marginal before. But, the vast majority of time, if you were not able to work a particular repeater or other station from a particular location, doubling the power won't help! If you were noisy before, then doubling the power usually helps with the "quieting" (noise reduction in the received signal).

    Since the difference between 50 watts and 75 watts is 1.761 dB, that isn't going to make much difference on the received signal. Even doubling the power, which makes a 3.010 dB increase doesn't make that much difference in the received signal.

    However, the radiation pattern from the antenna which includes "apparent" gain, can make a considerable difference in the strength of the signal. Also, losses in the antenna (like the usual "rubber ducky" antenna on a handheld unit has about a negative 10 dB gain), plus the radiation angle of the signal, make even more difference in the signal level received by the "other" station (repeater, etc.).

    I have been associated with commercial two-way VHF and UHF FM systems for almost 4 decades in one role or another (from field technician when I was in college to owing the Motorola reconditioned equipment center for the south-central United States, being the first FM Editor of CQ Magazine, to doing consulting work including design of antenna systems, grounding, etc.). Frankly, over the years I have seen just about everything that can happen with a radio system! But, of course, it seems like when I "think" that I have seen everything that something "new" crops up! However, at least 99 percent of the time what I have explained about power levels are going to hold true.

    Glen, K9STH
     
  4. WF7I

    WF7I Ham Member QRZ Page

    Glen,

    One of the biggest misconceptions many hams have is that doubling the power will make a huge difference. I used to be a believer in this as well until after I had started work in the cellular industry, and it finally dawned on me that twice the power is only 3 dB, which on a typical HF rig is only like half an S-unit! When seen in those terms, you quickly get the hint that unless you are really in a marginal situation, that extra half S-unit won't do a lot for you. Now, multiplying your power by a factor of 10 with that "leeeenearrr" is another story! But even then, you're not quite getting 2 S-units improvement.
     
  5. AC0BE

    AC0BE Ham Member QRZ Page

    Marginal operating conditions is the key word here- the little bit of extra power the V8000 has is why I bought one. Where I live, you can get far away from repeaters easily and the extra 25watts (or so) adds a little comfort zone to the outback.

    The only complaint I have of the V8000 is that I wish the basic settings were a little easier to program. I have to get the book out everytime I want to add a station or change a setting for the local repeaters.

    73 Steve
     
  6. KD4AMG

    KD4AMG Ham Member QRZ Page

    [​IMG] It may have been simplier for you to just operate a 2 meter rig that is EASIER to set up, program and change settings at a moments notice...

    and

    buy an amplifer that takes 40 - 50 watts ( or even less ) and amplifies to 200 - 300 watts. They aren t cheap, but might be worth considering for your area, should the ICOM not work out.

    Just an idea

    ---ai4ep---
     
  7. KC7JTY

    KC7JTY Banned QRZ Page

    I got one. The receive is sensitive enough, quite good in fact, but the front end could be tighter. Intermod & overload are problems on 2 meters. Seems to do much better with these problems on the railroad band where I spend most of the time anyway.
    Why doesn't the squelch on all the 2 meter mobile radios I've had so far have more effect? It would be nice to sq. all sigs below s5 if I wanted to (but can't). Tx for 1 sec and the fan comes on for 2 mins. I think a temp controlled fan would be better.
     
  8. K4UUG

    K4UUG Ham Member QRZ Page

    </span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (AB8RU @ June 10 2004,22:36)</td></tr><tr><td id="QUOTE">Hi everyone, I was at the Hudsonville IRA Hamfest and looked at a couple rigs and decided that I wanted a new 2M. So I settled on the Icom V-8000 , well I got more than I bargained for, full CTCSS, 4 power levels 5, 10, 25, &amp; 75 W. output, controls on the mic, turbo scan, 207 Channels, wow !  [/QUOTE]<span id='postcolor'>
    I have one of these V8000 radios mounted in my pick-up truck, I use the Diamond SG2000HD and the Diamond Door Mount with the Diamond coax,Diamond,SWR meter.
    I have noticed a little difference between the Yaesu FT 7900 at 50w with Diamonds SG7900 antenna and the V8000 at 75 w and the diamond SG2000HD but I think it is the antenna and not the power out put.So its iall about matching the right antenna with the radio.My SWR is 0.1-1.5 across the entire 2 meter band at 75watts.I belive this radio is well built like the ones Icom makes for public service.I use an SWR meter on all my radio's mobile and base.I have a friend in North Carolina who uses a V8000 as a base radio,he used 4 cushcraft 13B2 - 13 Element Wideband Boomer Antennas with staking kit
    on top of a 200' tower Hardline feed of 275' goes under his home and up thru the floor to his radio room.
    Simplex from base to mobile 150 miles is not uncommon.Awsome set up for 2 meter vhf FM communication. [​IMG]
     
  9. W9JI

    W9JI XML Subscriber QRZ Page

    </span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (KC0OZU @ June 13 2004,09:32)</td></tr><tr><td id="QUOTE">The only complaint I have of the V8000 is that I wish the basic settings were a little easier to program.  I have to get the book out everytime I want to add a station or change a setting for the local repeaters.

    73 Steve[/QUOTE]<span id='postcolor'>
    On my V8000 I found it ALOT easier to do everything with the DTMF mic, when you open up the book and start reading how to perform a function read how to do it with the mic instead of the buttons on the radio

    The mic is much easier to control the radio in my opinion.
     
  10. Guest

    Guest Guest

    Glen,

    Everything you say here is true, but one question remains:

    What about the &quot;capture effect?&quot; Doesn't even a 1 db difference in received signal strength make a difference?

    Here in southern California, where an unlicensed &quot;jammer&quot; (with a new amp and antenna) is making repeater usage a real pain, this could be important.

    73,
    Bill
     
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