There is no such thing as a "subchannel."


   Ya, ya, I KNOW  that's what "the thems"  are calling them,  but all that a "subchannels"   is, is,

a reg'lar, plain 'ol  "channel"  frequency,  and the "number"  of channels is "multiplied"  by the use of PL/CTCSS/ DPL  "tones."

There is NO subchannel,  the frequencies are all the same 16 or so channels,  and if the radio is set to decode some PL tone or other,  then that radio won't "hear"   a transmitter with some OTHER PL tone, ---but I guess you know?---   the signal will still be there.

Just because there are some 38 PL tones,  does not mean that 38 people can use the "channel"  at the same time.

I can't tell if the modulator components are all in there or not, but with the interest in AM,  at the very least the modulation transformer may be worth something to someone.

You might tear it down and get enough parts to make a small linear out of the   ---what everyone is calling---   the HF  section.   I'd agree, that's not 6 meters.

What appears to be the 2M section is not shielded, that's the two lines coming off the tube that has two plate caps, in there where the antenna relay is.

the round black dial is apparently a VFO that someone made out of a "command"  transmitter--known to some of us as "ARC-5's"


I can't see what the two tubes with caps are behind the 866's--are those 1625's or 807's?   I'd guess those are the modulators, and if so,  the black transformer on the corner is probably the modulation transformer.

(Actually, hard to say, appears you haven't shown us all of the back view.)

On the chassis with the ?4-125's?   it looks to me like there are two 5881's,  which would be modulator tubes for that section, anyhow.  Could there be TWO modulators?


By the way, with all the corrosion, dust,  and exposed terminals, I HOPE you aren't figuring on lighting that thing off!!!

If you erect a housetop/ mast top antenna and hook it to that THF6---or any other modern,  "wide coverage"  amateur handheld,  you can bet you will have some intermod and other types of (image) interferance problems.   That is because most modern handhelds have a VERY high sensitivity front end to try to squeeze  the best out of the "rubber duck",  and when hooked to an outdoor antenna,   the poor front end selectivity will show up.

There  IS something you can do about this,  investigate  buying or building various  "notch"  or "bandpass" filters, depending on what the interferance turns out to be.

So far as power line caused noise,  that is hard to tell--you'll just have to play that by ear.

Power line noise GENERALLY  hurts HF reception  more than VHF/UHF.

I'm not familiar with the 847,  but you might read (if you haven't)  the manual for the Ameritron keying interface:

http://www.ameritron.com/manuals.php

http://www.ameritron.com/products.php?prodid=ARB-704

http://www.ameritron.com/man/pdf/ARB-704.pdf

Well, first of all, we need to know what the radio IS.  An Icom 706, for example, doesn't even have a useable relay output as such.

My FT-1000MP  MKV Field, on the other hand,  will key my Ameritron AL-80B with  no interface needed, as will the old 735, and the (now unused)  TS-570.

I disagree.   I think you've not thought this out ENOUGH

Using HT 's might just be a real bad idea.  I know what you're thinking--low power, portable.

The bad side of HT's--real poor front end rejection, and no duty cycle.  They're  many times unshielded, unless you do shield them, adding to desense problems.

You might just find that you need to separate the antennas a lot more than a "few feet."

I have no idea what you're planning, but you might try something like stringing one antenna up a tree, try for as little as maybe 30 ft separation.  

The problem there, is, how are you going to materially effect range?  If one antenna is near the ground,  that can't help, much.  The other antenna WILL have to be vertically separated to cure desense,  so however high the lower antenna is, the upper one will, obviously, have to be just that much higher.

The problem with portability, is, if you use "cans"  (known as A duplexer)  or if you carry decent shielded coax,  this gets heavy.   Most of the "compact"   "notch" duplexers for VHF  are about 5 mhz separation,  any other type is big, heavy, expensive.

I wouldn't expect to be able to do this project with something as silly as rubber duckies.

I STILL think you should consider using UHF,  which would cure most of the problems.

You can use one of the little, compact mobile duplexers on UHF.  Motorola, and probably others, do make little "one box" repeaters that essentially ARE a pair of HT's  with a controller and duplexer.

Because of needed antenna separation, duplexer size, and so on, I remain unconvinced that doing this on 2 meters has any advantage over UHF.

Actually, buying, or building,  an UHF  portable isn't all that difficult.

However, 2 meters is something else again.  Because amateurs use such close tx/rx freqs,  the duplexer is very critical, large, and expensive, and not only that, but a certain amount of "banging around"  for the sake of being portable  won't do the tuning any good, either.

Also,  (especially) a 2M duplexer should have final tuning done "one site"  to take care of the above problem.

Last,  even difference in coax feedline, antennas, etc, can affect the "final" installation.

Unless you really, really really need a portable VHF  repeater,  I'd try to find a different solution.

Frankly, in the Pacific Northwest, there are TONS of unused or little used repeaters.   I can't imagine a situation, here,  where one would need a portable VHF repeater.

Well, you could convert "for"  4cx-250B's  and put it on the air, and keep looking for a pair of (harder to find)  4cx-350B's  (I think)


I say "I think"  because I can never remember for certain.   I believe, the 4xc 150  250  350  series uses the same socket,  but I believe the 4cx300 uses a "bayonet"  socket similar to the big 4cx-1000/1500

I have a VX-5, after  (still)  owning my old FT-50.   The VX-5 is ok,  I can't really compare to the Icom.  However,  I'd guess that with the crappy little bitty antenna that the VX-5, or ANY OTHER   6M  ht comes with,  I wouldn't expect much range improvement on 6, compared to 440 or 2M

I also have a Kenwood  THF6, and find it EXTREMELY  unhandy to operate.

A "cell blocked"  radio means that the microprocessor is blocked in such a way that you cannot RECEIVE   cell calls   in the receiver range ot the radio--which means the "old"  analogue   800xx  mhz area.   None of these radios will receive any digital calls.

The radio will not transmit on the cell band,  and you cannot "make" cell calls.

In the US,  receiving cell calls is now illegal, and there's not much up there to hear anyway.

There are many pitfalls to programming commercial equipment.  I'm not all that familiar with Mother Motorola,  but there are situations where you can "kill" the radio  by using the wrong programming,  or corrupt the codeplug with things like loose programming connections, etc.

First thing you need to do if find out what the error message means.   I'd start by posting a question at the batlabs forum.

Next, many commercial radios will not program down into the 2M band--unless they were already "there"  unless they are  re-aligned.   I've got some GE stuff that needs to have the VCO  retweaked, as well as some of the RF transformers realigned, before they will go into the amateur bands.

One thing about, this.   If you stick with it, you'll probably learn a lot.

Now that all the technical names have been doled out, the REAL reason, is that  far away and long ago,  even before "hams"  had licenses,  the early experimenters of their day mostly referred to "where" they were operating as "so many meters,"  rather than what frequency they were on.  Part of this was because all the equipment was so "drifty"  that no one was really "on" any certain frequency---something, in fact, that continued up to and after the invention of the crystal as a frequency control.

I don't know how to do that for you.   Assuming you can download and save the files,  you need to search the internet for the  "plug in"  to allow your browzer to view the "dejavu"  files.

Here, for example, is the one for Internet Explorer:

http://www.lizardtech.com/download/dl_options.php?page=doc


Once you have the viewer plug in downloaded and installed,  you can save, view, and print the files.

Go here:

http://bama.edebris.com/manuals/cde/ar22a


Which came from here:

http://bama.edebris.com/manuals/


Which is the (normally faster)  mirror site for "bama manuals":

http://bama.sbc.edu/


This particular file is in "dejavu"  format,  there is a plug-in available,   just search on Google.

If you download stuff from the main "bama"  site, it is normally slower,  but there are some things there that are NOT at the mirror site.

Also,   Microshafted "Internet Exploder"   can be set up so as to cause download problems.    Easiest way (for me) was to download and install the "mozilla"  browser,  which I use sometimes,  and when I do use the bama site.

From Bill Orr,

The Radio Handbook, twentieth edition

Chapter 17,  some suggestions on a choke for 21-54 mhz

48T  #26, space wound wire diameter, about 1 1/2" long and 1/2 x 3"  long ceramic form.  Series resonant near 130 mhz,  75 uh.

From the twenty-first edition,  a 6M  project with an 8877,  is using 54T #20  (evidently close wound) on 1/2"  dia teflon,  winding shown as 1 13/16 long.

From the twenty third edition,  a 3-400Z  project for 6, uses "3 uh"  48T, no 16 closewound on 1/2  "insulator"   (does not specify material)

The above Bill Orr book, the latest I have,  says the very same thing as the first quote above  (48T #26)

From the 2001 ARRL  Handbook for Radio Amateurs, section 13.xx

The suggest a reactance AT LEAST as high as the plate load impedance, and yet no series resonances near "any"  of the operating frequencies.   (They note that some commercial amplifiers have resorted to a bandswitched choke to avoid problems in multiband amplifiers.)

They say to short the choke with short, heavy braid,  mount in the position in the amplifier that it will occupy, and "dip"  the thing for series resonance.

That same handbook,  showing a 6 meter amplifier using a Svetlana  4cx1600B,  uses  40 t #20, 1/2"  dia, close wound

The '96  ARRL handbook,  a 6M amplifier using a 3cx800A7,  uses 40t #22, closewound on 3/4"  dia teflon.