I just ran across this on eBay.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=1374780132

Sure looks handy. By that I mean simple & straightforward.

Does anyone know of a S/W based version of this? Or where I might find the formulas it uses so I might model this using excel? Unless I'm missing something I'm not seeing anything this straightforward in the ARRL antenna handbook.

I have an Autek RF-1 Antenna analyzer and it sure would be nice if I could input found (and 'what if') values of L & C to determine resonant freq.

Thanks

I'm considering adding a grand old Collins receiver to the shack.

Since I would preferably like it for both AM SWL and amateur use I'm focusing my attention on finding a decent 51J-'N' model. Are there any websites dedicated to this series so I'll know which might be best suited for my use?

I'm not really looking for an investment. However, aside from the obvious generalities (e.g. condition, functionality, etc.) I'm totally ignorant concerning what I need to know to avoid getting burned. For example, what 'parts' should I make absolutely sure are included (I've seen quite a few available without the mechanical filters)?  I don't want to pick up something only to find I'll probably never be able to afford/replace that (insert costly/rare part here).

KC7CRR: If you would be so kind as to mail me a copy as well I definately would appreciate it. My address is correct on eHam (e.g. just look me up in the call sign database here).

Thanks & 73

I purchased a Logikey K3 keyer from another ham. All I got was the keyer (no manual, power supply, etc.). No biggy, the rear power connector is labled 12 v and there is an LM340 (5v) used as a voltage regulator at the input.

In the meantime I've been in contact with the company (Idiom Press). They're being VERY adamant that I should NOT use a 12v wall wart unless it is REGULATED and FILTERED (they're emphasis, not mine). Instead, I should only use an external, regulated 12VDC power supply ("Do you have a 12 volt supply in your shack, perhaps to power a 2 meter rig or the like? That would be ideal").

Seems like overkill to have to power a simple TTL (albeit microprocessor) based CW keyer with a big 'ol external PS to me... especially since the input is already regulated via the LM340. Is there any reason to be concerned the LM340 can't handle regulating voltage/current from a decent wall wart? Before I got the warnings I already hooked a 12v 500ma wall wart to it and it seems to work just fine (although not yet connected to the rig). Is there something else I'm missing here?  Inquiring minds want to know!

Wow... talk about perfect timing. I have essentially the same limitations due to condo CC&R's and was considering the same approach (ridge dipole or perimeter loop) to improve my current attic based 'antenna farm'. I even have concrete roof tiles as well (so thanks all for the good tile info)!

So yes, please report your results.

Now if I could just figure out how to get up to the 2nd story roof (no 20'+ ladder here) and/or not attract attention to exactly what I'm doing.

NQ4A (et al),

I'm in a similar situation (a townhome condo with antenna restrictions). I currently have a 'slinky dipole' (junk, to be relegated to SWL listening) and a 20 mtr Isotron (OK but single band) in the attic.

I've been seriously thinking of putting a horiz loop antenna around the perimeter of my attic. My attic (more like a crawlspace as well) is approx 25 ft per side with 1/4 of it somewhat taken up by an 'intrusion' from having a cathederal ceiling in the master bedroom. Man is it going to be a PITA to install this but a horiz loop appears to be my best shot at really being able to get out.

Couple questions:

Think it might be more advantageous to create a full wavelength loop by employing a multiple loop configuration (e.g. like a large coil)

Is it better to place the tuner at the feedpoint as N4QS did vs at the xceiver (e.g. at the beginning of the feedline)?

Do horiz loops seem to like twinlead (or ladderline) or coax better?

Please forgive him... he's just frustrated (This is what happens when a CB'er can't pass the tech test).

For those of you that have/used them, I'm just wondering if the integrated digital bandscopes on the newer 'state of the art' rigs (ala the IC-746 etc.) are indeed that functional/useful.

I think I would almost prefer seeing manufacturers spend the extra design/manufacturing cost on providing an IF (not audio) interface for PC based spectrum analyzers (ala Spectrogram) or better yet, an outboard (?) PC based analyzer option that would allow computer control so you could 'point & click' on an area of interest and thus have the PC control/tune the rig.

While they indeed peg the cool factor meter, what say you owners of rigs with digital bandscopes? Are they truly useful or does the 'novelty' wear thin after long term actual use?

Problem is, Dayton comes only once  year, hamfests about once a month around here. And the only store dedicated to amateur radio here in Austin could seem to care less that you even walked in the door and appears to know little about anything they're selling.

Ebay is 7X24 and my experience with dealing with (real) Hams on eBay has been nothing but positive. Ditto with the eHam classifieds.

Another nice thing about eBay is it's a 'reference'... you don't have to buy anything while learning a LOT about what's out there (equipt, parts, features, accessories, etc.). Lots of the time even the gear pics are SO much better than even the ones you find on manufacturers sites. eBay can be quite educational in a literal sense.  

Agreed, I know there are those that like to bash eBay but if you watch it pretty close there are occasionally some fine deals to be had.

Caveat Emptor extends beyond the actual item tho. I learned a $600 lesson once that despite the sellers assurance & stellar reputation you must absolutely insist on good packing. Now I won't complete a transaction until I'm 100% positive the item will be packed/shipped to my 'specs' (even if it means a potential negative feedback as a non-buyer). Since there is no assured recourse for a bad deal I've found the Golden Rule of eBay is to communicate with the seller thoroughly, resolve any questions, remove ANY/ALL doubts prior to bidding. And trust your instinct... If you think you should pass on an item do it. It's OK because another one just like it (or better) will show up soon enough anyway.

Mike KD5QPF

One thing I do find interesting about some of the estate sales I see on eBay is the 'I don't know nuthin about this thing' sellers sure seem to have a good idea of what reserve to set.  

Sean (aka "K0PSK") brought up a valid point:

I submit eHam is at least a 'hopefully for profit' website. I have no problem whatsoever with that since providing & maintaining a website is not free (or even cheap these days). Nor do I have any problem with people wanting to be compensated, however slightly, for their time/trouble in providing this website.

Bottom line, it is designed, operated and thus 'owned' by a group of people. Hence it is indeed their call and perogative to direct and manage the content at their whim & pleasure.  IMHO the current management is doing a fine job in this regard.

Something Sean may have overlooked about the web (and websites) is its 'democratic' nature, e.g. if you don't like a website, it's content and/or how it's managed/moderated you can simply not visit anymore.

Something the eHam forum moderators may have overlooked is the ability to block the IP of those attempting to undermine the community and the intent of the website.

I tried to get a copy of my expired license (KA4LSU) for 'nostalgia' sake as well. I know I have it somewhere but jeeze, there's no telling where it's tucked away after 20 years.  Sent a 605 to the FCC requesting a duplicate and they responded they don't provide duplicates of expired licenses.

Been there, done that and already looking to replace it. Best SWR I can get from this "dipole" is a bit under 3:1 at a resonant freq of 6.74 Mhz. Any/all inquiries to usa2way to improve these results have thus far gone unanswered.  Sorry, I know this isn't the product review forum but I can't help NOT recommending it.

I agree the noise cancelling feature wouldn't seem to be very advantageous in an amateur radio environment (except, god forbid, possibly in some emergency situations)... rather, it's the presumed design focus on intelligibility that Pete mentioned.

Given the plethoria of different models, does anyone have a particular model they feel is best suited for amateur radio use? e.g. impedence matching, ease of modification, etc.