" Steve,

Thanks for the information. A quick Google search for 'Cool Amp' revealed the product you specified.

It looks very interesting. I read the product information, but I am not sure how this stuff bonds to copper or its durability. The directions state that you wipe it on with a damp cloth and it deposits .001" of pure silver. I will have to do some more investigation.

I greatly appreciate the info as always!

73,
Doug - N9XTF"

======================================

    The "Cool-Amp" works as claimed, and the durability is no different than electroplated material.  It WILL last.  And if the surface is clean and free of grease (including fingerprints!) it goes on fairly easily and gives a uniform, but thin finish.  (It's just as susceptible to scratching or abrasive removal as any other type of plating method.)
    While the "Cool-Amp" product seems expensive and it seems you have to buy a large quantity, they DO have a more reasonably priced "trial kit" that (if I recall) is less than $50 and can cover a lot of Amateur Radio projects.)

    Ag plating will not have a significant effect at HF, other than to prevent corrosion; Ag Sulfide and Agoxide arealso both better conductors than pure copper, and certainly much better than Cu oxide or Cu sulfide.  (The main pollutants in air, aka SMOG.)

    If there's truly a need for Ag plating, then electro methods can deposit almost unlimited amounts (depths)given enough time, expertise, and money.  But the chemicals are toxic and not normally a "DIY" type of home endeavour.

Could be the dreaded but insidious "Eye-Dee-Ten-Tee" syndrome.

As said already, you get 6 Meters by stepping through the bands.  (Obviously, 6 Meters comes after 10 Meters; the default [at least on mine] WAS 50.125 MHz.)  THEN, make sure you are using the proper antenna connector.  You CAN toggle between Antenna 1 and Antenna 2 with "ANT" button.  (Same as $4 on the keypad on the left.)
    Be aware that while you MIGHT be able to make contacts with a "wire," you would need an external tuner, which is not very efficient on 6 Meters.  The internal tuner matches only a very narrow SWR range.  Switch it off when using the external tuner.  But you are STILL much better off using at least a dipole for 6 Meters.  Even a 3 el. Yagi isn't much bigger than a TV antenna.

    Good Luck.

Are the radios in an enclosed area?  If so, you will have to provide a fan for ventilation.  Otherwise, they shouldn't be overheating, unless they were modified.  If that's the case, you're stuck with the overheating and a possible Rileygram.

One way to decide on whether a filter will benefit you (and it it's sound is something with which you can live) would be to find someone (a fellow Amateur, a store like AES or HRO) who can demonstrate the improvement provided.  It doesn't really have to be the same model or even a Kenwood; while all radios sound difference, the comparative difference between filters will still be applicable.  If the 1.8 kHz filter sounds too unnatural, it probably wouldn't sound all that good in your radio, either.  If you can, take a pair of your own headphones when you do a comparison, since speakers especially can "flavour" the sound of a radio.

If you're going to spend money on a filter, goiung from the default bandwidth of 2.4 kHz to 2.1 kHz probably won't yield that much improvement.  The 1.8 kHz will give you the "best bang for the buck," meaning the greatest improvement; but as already said, will sound "different " than the stock bandwidth.  Wit a lot of QRM, though, it can make a significant difference.

    BTW, Kenwood has discontinued that series of filters, so supply is limited to what's in the inventory.
    Inrad makes excellent filters, and make a 1.8 kHz filter, which sells for a bit less than the Kenwood unit.

The myth about 811 amplifiers in general is, folks think that by replacing the finals with 572Bs, their tube life problem will be solved, and it very well might. However, the power supply is still what it was before the change out, and THAT is the limiting factor.

Alan, K�BG
www.k0bg.com  

======================

    To add to Alan's comment, 572's won't SOLVE any problems; in fact, they may only aggravate a situation.

    As he said, one of the greatest reasons for premature 811 failure is being overdriven.

    One of the BIG problems is that while the 572's are more rugged, and they don't produce more OUTPUT, they can withstand a greater degree of overdrive without failure, but that only makes a signal dirtier.
    More tolerance to overdrive is NOT an advantage; in fact early 811 failure should be a wake-up call that the tubes are likely being driven too hard, or some other operator-induced problem exists.  572's don't really SOLVE any problems.

You definitely need a shorting stick, but it should have a (relatively) high resistance included, otherwise, shorting the HV before the bleeder has started to work can cause a large surge current and possible destroy some components.  Apply the shorting stick, then leave it in place and brew a cup of coffee, or read the front section of the newspaper.  Come back several minutes later. and with the shorting stick still in place, apply a jumper wire (with alligator clips on each end) between the HV and ground.
    Only then can you remove the shorting stick.
    Next, use a volt meter on the highest voltage scale to probe and make sure you didn't forget any areas than need to be discharged.  Use additional jumpers to insure all voltages are reduced to zero. THEN do your repairs.
    While you have the amp shut down, subdued, and powerless (pun unintended?) to hurt you, take time to inspect (and even check) all the parts to look for unsuspected damage or deterioration.  Leaking capacitors, charred resistors will need to be replaced, even if they haven't completely failed.

    THEN (and this is VERY IMPORTANT) remove ALL of the shorting jumpers.  (The power supply will appreciate it when you turn things back on.

    The best thing is to get an experienced Amateur to guide you through the process, at least the first time.
    While "sending the amp back to the manufacturer" is a possibility, it's (IMHO) poor advice.  We ALL had to learn, including learning about working with HV in a safe and sane manner.  Follow safety suggestions and procedures, and YOU will become one of the experienced Amateurs in the future.  You won't learn anything by shipping the amp off somewhere to get it repaired or retubed.

    Be careful, and good luck.

Why not go to the Heil website and ask Bob himself?  He tries to answer e-mail quickly.

The only legitimate use of a "modified" Amateur Radio is current participation in MARS, and the MARS organization will be able to provide the modification information upon request or refer a person to the manufacturer, who will provide the mod information upon presenting them with a copy of their MARS authorization.  Simple.  Concise.  Legal.  No need to ask here or anywhere else on the Internet.

Contact this fellow.  He apparently worked for HeathKit (Standard made some radios for them) and had worked as an authorized repair center for Standard before they left the market.  He evidently bought out Standard's parts inventory when they left.  According to those that have used his services, he does good,work with a rapid turn-around.
    The info is about 4 years old, so I hope it's still current.  I don't know of any other repair facilities that specifically work on Standard Amateur equipment.  I have 2 H-T's and a mobile, and all are still functioning well after 15 years or so.  (The H-T batteries are a bit aenemic, though.)  
    Good luck.  I hope Matt can help.



Matt Adrian  KD8ZB
SAR Technical Services
1792 Nash Drive
St. Joseph, MI 49085
TEL: 269-429-2334
www.qtm.net/~sarts/sarts.html
sarts@qtm.net

 by LA4RT on October 7, 2007    Mail this to a friend!      How do I tell if I've got a G or not? Is there any difference in the menus, for instance?

    There are menu differences, but the ID label (with the serial number) will indicate whether it's an original or a (G) model.  If it doesn't say TS-570D(G) it's the original version.

Contrary to popular belief, not all mics are interchangeable.  Icom radios typically require special (electret) elements, and provide phantom power on the aidio line; incorrectly connecting an improper mic type can damage the mic, the radio, or both.
    But as to Yaesu, you should check the individual manuals, to ensure the connectors are exactly the same.  (They most likely are, but verify to be sure.)
    Do either mics have additional functions besides PTT?
    If one or the other has a keypad or other function buttons, then interchangebility may be more complicated.
    A call/e-mail to Yaesu should answer your question definitively.

    But I don't understand the problem you describe with the one microphone.  Is it the cable that is damaged?  If so, that should be relatively simple to repair or replace.

If the connectors on the LMR-400 are in good shape and properly installed (or you choose to install new connectors, not that bad an idea if the originals are questionable) it would be preferable to using RG-213/U at VHF or higher.  Not because of the loss in the additional length of RG-213/U, but because the LMR-400 has inherehtly lower loss than '213.

    (It might be wise to replace the connector(s) on the LMR if exposed to the elements; doing so would also allow you to inspect the cable for possible water/weather damage.)

Unless you need the extra coax in the shack for interconnections, just leave it.  (You CAN coil it with at least a 12" diameter coil; think: size of a reel from the manufacturer...)

    The additional loss in only 16' will be only a few tenths of a dB at most, it will not be significant or noticable; barely measureable.  (Even with a high SWR; and if you DO have a high enough SWR to make the loss of 16' "significant" you will have wasted most of your signal in the other portion of the coax.
    Some people obsess over a tenth or so of a dB in feedline loss; if it's THAT big a deal, then a better feedline and better antenna should be considered.  If a person wants to split hairs on loss on VHF, better feedline would more than make up for the loss in 16' of RG-213/U.