{If the FCC was smart, They would open 11 meter all the way up to 28.000 for cb. NOT ALL CB IS 40 CH AM Radio.... 1}

Hey... why don't we just have the FCC open up all freaks!... um Freqs... hey... that way I could compete with WABC and all the other commercial TV and Radio Stations out there...... Gesh!   Get a clue!

Hi Again Kevin,

I think what you are asking is if this can function as a 2 meter repeater.   And the answer would be no.

To operate a repeater on 2 meters for example... you need to have a way of separating the RF transmit from the receive.  This is because the transmit and receive frequencies are so close to each other and the Repeater will be both transmitting and receiving at the same time.

Normally this is done in either one of two ways:

- Spacing....   Physically locating both the transmit and receive antennas a good distance apart. On a repeater... the receive and transmit sections will have their own separate antenna connect to make this possible.

- Cavity Filter. Cavatiy filters are filters which exhibit a very High Q (Quality) in that only the desired frequency is rejected while the other frequencies are alowed to pass. Several Cavity filter are connected together together to achieve the desired results.  Cavity filters are very large and would be difficult to lug around for portable repeater operation unless you had a truck or something to carry them in.  Use of cavity filters enables you to Run both the Transmit and Receive sections of a Repeater from the Same Antenna.

For Cross band repeating... the Receive and Transmit frequencies are spaced much further apart.  A device called a Duplexer give you enough RF separation to allow the repeat capabilities.

I hope that maybe I at least understood your question correctly and I hope that this helps you understand a little better what you are trying to do.

73,

Randy

Hi Tom,

I started building antennas back in 1975 for 11 Meters (before I was a Ham).  A fellow CB'er of my had given me a copy of the ARRL Handbook.  This book contains a wealth of information not only on building different types of antenna's for all bands from vlf through ehf... but also construction, radio wave propagation, transmission lines, etc.

I have continued to upgrade my ARRL handbook not because I like the ARRL... but because it is an excellent book.

This is one book that you will never need to throw away!

Good Luck!

Randy

I would just like to make a clarification regarding Simplex repeaters so that there is not any confusion.  Basically... Simplex means... 1 Frequency... or you receive and transmit on the SAME frequency.  Simplex repeaters use a recording device to record a message... then later after the message is complete.. play it back for everyone to hear.

The type of repeater described here is actually Semi-Duplex. You will Receive(VHF) and Transmit(UHF) on different frequencies although not at the same time (Your Cross band repeater actually does the opposite receiving on UHF and transmitting on VHF).

Full Duplex is the ability to Receive and Transmit at the same time... such as on your telephone... in other words... someone could interrupt you while you were talking. One might argue that the repeater itself is actually Full-Duplex since it is Receiving and Transmitting at the same time, however from the users perspective... only one action can be performed at a time (receive or transmit).

Hi Steve,

I believe that even at 30 ohms... if the antenna is tuned properly, your swr will still be well below 2.0 to 1 and perhaps better than 1.5 to 1.  Depending on how critical you are on your SWR you may not need any turner at all.  I remember many times back in my CB days building quarter wave groundplane antennas.  And I was always able to attain an SWR lest than 1.5 to 1.

Good Luck on 30!

73

Randy

Hi Max,

I don't believe that you will achieve any Gain from using the antenna's in this configuration although you may become more omni directional.

Have you thought about using an Inverted V?  This will give you a practially Omnidirectional pattern.  The gain will be slightly less than that of an actual Flat Top dipole, but I believe that you would achive about the same thing by the configuration that you are talking about.  Also, the impedance more closely approximates 50 ohms in the inverted V configuration.

I have heard that you can get 15meters from this but I have always opted to create another dipole for 15.  In my current configuration I have 10, 15, 17 and 40 meter dipoles all connected to a single feedpoint. and it is in a cage configuration.

I hope this gives you some ideas.

73

Randy

I realize that this is not necessarily a Ham Radio issue... but I thought that some of you might find it interesting.

The following link to a page on the FCC website outlines how and why it is illegal for any entity (including ccr's) to prohibit the installation of Television Antenna's expect under certain circumstances (safety issues, historic... etc).

http://www.fcc.gov/mb/facts/otard.html

73,

Randy

Thanks Matt,  Now I have a better idea of your situation.

With the new information that you have given us I have two more ideas.

1.  You have a bad VCR and somehow the 2 meter frequencies are mixing with something in the VCR causing the Interference on Channel 3.  One way to check this is to connect your antenna directly to the TV and put it on Channel 3.  If the interference is no longer there... then the issue is most likely with the VCR.

2.  2 Meters is mixing with an external source. Do you have a local FM brodcasing station or perhaps A local TV station on channel 6. If it is true that you are picking up a Repeater 28 miles away... then something has to be turning your VCR into a tuner capable of receiving on 2 meters. I guess that another question I have is if the intereference is contious (whenever someone is talking there is interference) or if it is intermittent.  If it is intermittent... then you can suspect an external source that does not transmit all of the time... like a paging transmitter or other local communications transmitter.

Using a different VCR will help to determine if it is coming from an External source or if it is a bad VCR. If it is coming from an External source then it is still possible that the mixing could be taking place within your VCR. Do you have an neighbors nearby that complain of the same problem?

If it is mixing in your VCR then the stub filter that the gentleman mentioned previously may help.

As a side note... the channel 18 than you mentioned that is on 2 meters is actually CABLE channel 18 and not the standard UHF Channel 18 that is on your TV.  You would not receive Cable channel 18 on a TV Antenna.

I hope that this information helps to lead you to a solution.

73,

Randy

I think that the tuning stub sounds like a good Idea, but it may not work.

As you know, 2 meters is 144-148 mhz.  Channel 3 on your television is 60 - 66 mhz. So if an overload is occuring one my question why it is only happening on Channel 3.

One suggestion that I would have is to try and use the Tuner on your VCR instead of your Television to tune to the channel that you wish.  Maybe setting the VCR to channel 4 (so that the VCR works when the TV is on channel 4) and then changing the channel on the VCR to channel 3. I have seen this help on an older Television when I was receiving interference from a local Police or Fire Dept.

You may want to try some other experiments.  Can you locate your radio close to the Television in question with a portable Antenna and see if the interference occurs.  Or how about using a Handie Talkie.  These types of experiments may help to isolate the cause of the intereference. Maybe your radio is putting our spurious emissions in the 60-66 mhz range or which is a harmonic there of.

Good luck, and let us know if you find the problem and how(if you are able) to solve it.

73
Randy

Hey,

I think that it's a great idea.  I was listening on 10 Yesterday on  my way home from work and heard several beacons.... one of them in Mexico.  But... I did not hear anyone talking (cw or ssb).  I even tried calling CQ for about 15 or 20 minutes.  Still... nothing...   I think that it would be nice to know when people are there and not just when the band is open.

Thanks,

Randy

When you Invert or reposition the elements on a dipole it will have a detuning effect on the antenna.  Also, the type of wire that you are using as well as the height above ground can have some effect on the total length of the Element.  At 75/80 Meters where a wavelength is very large, a small change in resonance can mean a change of several feet in the total length of the antenna.  

I have found a couple of sites with some information regarding Inverted V's.  Hopefully they will help you.

http://www.flashwebhost.com/circuit/antennas_for_ham_transmitters.php

http://www.angelfire.com/mb/amandx/dipole.html

Good Luck

AC4FD

ARRL Antenna Handbook!

Just a thought!

I know that they have several article regarding Multiband Verticals (as well as dipoles and other types).

Here is one article from ARRL's website that you can access even if you are not a member:

http://www.arrl.org/tis/info/pdf/7806016.pdf

If you are a member there are many more.

Good Luck!

AC4FD

Funny... I was looking at the same thing myself recently... This will get you started:

http://www.arising.com.au/people/Holland/Ralph/CMBalun.htm

http://www.io.com/~n5fc/balun_1-1.htm


73
AC4FD

Ok... I have done a bit of research on this myself... mostly on the web.. and have found some inconsistencies... but here is a quick run down:

NiCd's:

   -LifeSpan: = 1000-1500 Recharge cycles
   -inexpensive
   -Hi Current Applications
   -Needs full (not complete) discharge/recharge cycyles to have maximum lifespan (to avoid Memory effect)
   -Lowest Capacity  (typical AA's up to 1200 + Mah)
   
NiMh:

   -LifeSpan: = 500 + Recharge Cycles
   -Handles partial charges and recharges from partially discharged batteries better than NiCd's (Less Memory effect)
   -Becoming much less expensive
   -Better Capacity than NiCds (up to 2200 or more Mah for AA's)

Li-Ion:

   -LifeSpan: = About 2 years Typical.. the lifespan for Li-Ion batteries is not based on the number of cycles... but instead on the chemistry of the battery.  I have not checked no this lately.. .and it may be getting better.
   -Little or no Memory effect
   -Most Expensive
   -Highest Capacity
   -Does not conform to normal battery sizes.. therefore .. you cannot change from NiCd's or NiMh batteries to Li-Ion without a lot of work.  NiCd's and NiMh come in 1.2V cells where as Li-Ion come in 3V Cells.

I have compiled a good bit of information on the subject.. though much is out of date and may be inaccurate.  You can check it out at:
http://www.qsl.net/ac4fd/

Follow the link for Battery Information

73
AC4FD

I always thought that 28.450 MHZ was considered the calling frequency for 10 Meters.  Am I wrong??

Randy