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 21 
 on: Yesterday at 08:54:51 PM 
Started by KD9BIX - Last post by N8AUC
Ham YLs never look like that so the promotion exploits the fantasies of tubby old Ham men who can never have such a girl on their arm.. Shocked

You've probably never heard that old song, "Never make a pretty woman your wife".
Listen to those lyrics carefully. There is some serious wisdom in there.



 22 
 on: Yesterday at 08:54:16 PM 
Started by W1REJ - Last post by AA5MT
I talked with Rohn several years ago, and the maximum unguyed height is 33 feet.  Not sure, but I think it was with the tower secured to a standard roof support at the first floor roof level.

Tom

 23 
 on: Yesterday at 08:44:07 PM 
Started by KW4CQ - Last post by AA6YQ
[
What does my Authority on the forum have to do with your not being able to "get" the Ethical problems of your posts?


Your view of what's ethical is irrelevant.

 24 
 on: Yesterday at 08:32:07 PM 
Started by K5TED - Last post by ZENKI
Certainly more than enough receiver performance but its transmitter will always remain on the bottom of the pile like IC7851.

 Using excuses like "you can turn down the power" to have a clean drive signal is a pathetic design excuse for not designing the PA properly. So if you want a 100 watt clean signal you need to buy a 200 watt radio so that you can have semi clean signal at 100 watts. The ARRL needs to stop making excuses for radio like the IC7851 and IC7300 whose transmitters are from clean.

When i start seeing transmitters  whose IMD is suppressed 50db at 5khz or have 3rd order IMD  performance of around -40db and 11th order around 70 to 80 db I might start having respect for these radios.

We just fooling ourselves these receivers with such high IMD dynamic range are some how going to save us when its rarely going to be noticed in the real world. What would save us is having transmitters with the best performance. Even the ARRL finally acknowledged this in a subtle way in the review of the IC7851. We need more transmitter performance improvements The IC7300 would have been a perfect radio in every way if it did have a cleaner transmitter and fully calibrated S-meter and waterfall, we could have turned new page in ham radio design.  Maybe Icom will considered these improvements in the new IC7600 version of the IC7300. We can only live in hope that we dont get another radio with a terrible transmitter performance. Maybe they will get it one day!

It will nice waking up one day with a radio review that has glowing receiver and transmitter performance. Nobody ranks transmitter performance which is a shame. If there was a league table of transmitter performance like the Sherwood list on receiver performance hams would understand what all this preaching is about.

Direct link is:

http://www.arrl.org/files/file/protected/Group/Members/ProductReview/PROD_REV_0816.pdf

But you have to be an ARRL member and logged in.

I did notice that the 2 kHz two-tone dynamic range is 100 dB with IP+ on and the preamp on. Should the IC-7300 rank be moved up in the Sherwood table?  Wink

 25 
 on: Yesterday at 08:24:50 PM 
Started by AF5CC - Last post by N3QE
Don't forget the Supreme Court!

Are they a DXCC entity now? There's only 8 of 'em.

 26 
 on: Yesterday at 08:21:27 PM 
Started by VE3VEE - Last post by N5VYS
FM/T93Y    2003-11-26 via LoTW.

Obie-N5VYS

 27 
 on: Yesterday at 08:08:41 PM 
Started by AK0B - Last post by KD8IIC
  Yes, That would be a fun experiment! As stated, the ARRL Handbook from '77 has a 160m spiral wound vertical project and they specify winding a half wavelength of insulated wire evenly spaced on a 20-25' fiberglass mast or wooden pole. The mil surplus 44inch stacking mast poles wold work FB. Give it a shot... A 1:1 current balun should work it ok without a tuner I'd think es a couple of 15' radial wires.
 Currently I can be found at 10.130-132kHz using a TV Twin-Lead folded dipole inverted Vee or a 80m Doublet in the mornings and afternoon hours, email me to sked. Info on the "other" ham web site.  73 lane n8aft

 28 
 on: Yesterday at 08:02:48 PM 
Started by KB4MNG - Last post by N3QE
Quote
I agree completely that the QSK board is easily damaged in tube arc-over. But it's an exaggeration to say the parts aren't available through distributors. Mouser has 26000+ DIP CD4011B's in stock, and there are plenty of superior NPN and PNP transistors. The bias transistor ESPECIALLY needs an uprated replacement, not the cruddy original-spec one, and adding zener protection around it is especially wise.

The number on my ICs is not carried by Mouser, nor were any of the transistors.  The transistors found on my boards were not those shown in the updated schematics.  None of them were available at Mouser or the other USA parts houses.  You seem to have some info many of the rest of us do not have, but could certainly use.  Perhaps you can recommend a replacement for the 2N3055 bias transistor and others, such as the transistor that controls that bias transistor.  I believe that is a MPSW42 on my board and all the replacements I've found are also obsolete.  Are there other better 100 V 1 watt transistors available?  Thanks in advance for your help in identifying the devices.

The MJ15001 was the Ten-Tec recommended upgrade to the 2N3055. The upgrade has a 140V rating (as opposed to the original 60V for 2N3055) but will still tend to fail shorted in the case of a tube arc. I recommend also "wrapping" a 60V transzorb around this transistor (e.g. across the 150K 2W resistor used to develop bias voltage, and is shorted out by this transistor.)

Mouser 60V Transzorb part number: 625-5KP40A-E3/54

Mouser MJ15001 part number: 863-MJ15003G

The MPSW42 is mostly obsolete today. KSP42 is equivalent (300V 0.5A). Mouser part number 512-KSP42BU

None of these parts are all that exotic. The cost of these parts is completely trivial compared to the HUGE PITA it is to get to the parts in the amplifier. It is such a pain to work on these. That's why I recommend the transzorb.

 29 
 on: Yesterday at 07:37:48 PM 
Started by KM3K - Last post by AA4PB
About an hour - no more than two per device.
Gene K3GC

Once you get it started it will take care of itself so you can do other things around the house and just check on it once in a while.

 30 
 on: Yesterday at 07:32:48 PM 
Started by AF5CC - Last post by K4HB
Have you heard the murmurs coming from Texas calling for a Texit?  Eight more years with a Democratic president and not only will Texas be looking to secede but it will become a roar and all those red Southern states will be roaring along with Texas.

Sounds like a plan.

http://www.k4hb.com/luke.html

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