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Re: Durable small hex (etc) bits?

 

¿ªÔÆÌåÓý

Radu-
amazon or where ever, I have been using them for eons...good quality.
two sets one metric and the other imperial

Wiha 35392 5 Piece Mini L-Key Short Hex Metric Set

hope that helps

¸é±ð²Ô¨¦±ð

On 6/30/24 8:51 AM, Radu Bogdan Dicher via groups.io wrote:

Hi all,
I'm often running into the situation where, trying to remove to replace knobs on HP (and any number of brands) units, I need to use very small hex or other types of bits which get ruined very easily, sometimes on first use. These bits are from sources such as Amazon, where very good assortments and sets are easily available. The steel they use may not be of top notch quality.?

Is anyone aware of a source of hardened, extra-strength bits? Or maybe sets of drivers?

I am specifically asking for small bits typically needed for this kind of job. Impact-grade bits need not apply... At least I don't see an overlap in that Venn diagram.?

For instance, for the HP 6236B knobs, I apparently need H1.3 bits. All of my tougher sets (Harbor Freight, etc.) go as low as 1.5, but not smaller. I ruined my Amazon set's H1.3, then tried a couple other types (which I also ruined), and I'm afraid I'm at this point ruining the knob's set screw.?

Thank you,
Radu.?

Durable small hex (etc) bits?

 

Hi all,
I'm often running into the situation where, trying to remove to replace knobs on HP (and any number of brands) units, I need to use very small hex or other types of bits which get ruined very easily, sometimes on first use. These bits are from sources such as Amazon, where very good assortments and sets are easily available. The steel they use may not be of top notch quality.?

Is anyone aware of a source of hardened, extra-strength bits? Or maybe sets of drivers?

I am specifically asking for small bits typically needed for this kind of job. Impact-grade bits need not apply... At least I don't see an overlap in that Venn diagram.?

For instance, for the HP 6236B knobs, I apparently need H1.3 bits. All of my tougher sets (Harbor Freight, etc.) go as low as 1.5, but not smaller. I ruined my Amazon set's H1.3, then tried a couple other types (which I also ruined), and I'm afraid I'm at this point ruining the knob's set screw.?

Thank you,
Radu.?
Re: BNC Frequency Limit

 

The 'C' is "Not" a bayonet 'N'.? It is much more like a giant BNC, with a much greater total distance between inner and outer contacts than any N type.? (Within the mating parts at least.)?

Plus the contact surface area is much more generous than many others of the same overall outside dimensions.

But like the BNC, it's mechanical stability & longevity is poor.

I know as I've had to replace too many of them.

They were popular for valve(tube) linear Anode(plate) DC power interconnects a while back.

73..

Dave G8KBV.
Re: BNC Frequency Limit

 

No wonder they went out of business.? :)
Re: Several problems with Agilent 54810

 

hello,
I just did another test:
Only on the motherboard CPU? Atlas 757 and the video PCI card (66525).
The additional video module card (66502) is present, but not inserted into a PCI slot, and is only used to interface the power button with the acquisition board to the power.
The wire of the connector to the black light? pin 5 is diconnect from the VGA card? and grounded brings up the LCD screen
At this time the LCD screen works

So the chips 65550 on the video card don't seem to send the signal to ground to active the back light.
why???

20240630_154158.jpg
inside.jpg

Re: BNC Frequency Limit

 

Take care.? A 'N' plug centre pin Haa a larger diameter than the pin in a BNC plug, so you risk damaging the BNC socket centre receptacle if you force things together.? (Similar risk if it's a TNC socket.)

Maybe the counter once had a TNC input socket?? ?They are generally good to more than a few GHz.

73.
Re: BNC Frequency Limit

 

¿ªÔÆÌåÓý

Dear All,

If you measure transmission and match through a BNC plug/socket pair, the main issue seems to be resonance and radiation at the interface, due to incomplete seating of the plug outer connector.

Putting slight sideways pressure on the plug, causes a suck-out in transmission that moves around in frequency, often in the 5 GHz region.

Yes, 4 GHz is a good upper limit to use, though if you are concerned about signal leakage it might be safer to stay below 1.5 GHz.

Telegartner in Germany make some BNC connectors and adapters to closer tolerances than is usual- I have used these when I need to make measurements on items with BNC interfaces. There is less sideways play and VNA results are correspondingly more reproducible.

The precision N connector (the one with the non-slotted outer) needs to be torqued carefully to avoid a similar resonance problem.

For work below 10 GHz, the slotted design is much less critical of torque.

Regards,

Alwyn

?
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________
Re: BNC Frequency Limit

 

A "VHF attenuator" which is only good to 100kHz for 250 bucks? No thanks!
Re: HP3048 data file format?

 

Thank you very much John!

Found the function, quite a long one :-)
Will keep you updated, but don't hold your breath. Currently I have a rather painful health problem (kidney stone), so my programming zeal is kind of low at this time.

73, Marko Cebokli
Re: BNC Frequency Limit

 

¿ªÔÆÌåÓý

So here¡¯s an oddball connector usage from the opposite end of the spectrum - a perfectly good HP 355C VHF attenuator (BNC connectors) has been bastardised and is ?being used as a 600 ohm 1dB step attenuator with a maximum attenuation of 12dB¡­ It¡¯s currently on the local internet auction site and the seller ONLY ?wants $NZ500 ($US250ish) for it!

DaveB, NZ

?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Tom Lee
Sent: Sunday, June 30, 2024 06:54
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] BNC Frequency Limit

?

The word "limit" should not be interpreted as a fixed, discrete boundary that separates "useful" from "useless". The world is analog, so it's best to consider what is really meant in a given circumstance.

For a frequency counter to function properly, all you need is to preserve the zero crossings and some minimum amplitude, so that's a fairly forgiving application. That said, I am surprised to hear that your counter's 22GHz input uses a BNC. High-frequency counters often have a couple of connectors, one covering up to a couple of GHz and another above, but I've never seen or heard of a BNC being used in a commercial instrument for 22GHz -- could you let us know the instrument model? Or is it a homebrew counter?

That aside, in other situations you might need to worry about impedance mismatch. And that's where a typical BNC connector has unfavorable characteristics as you increase frequency. The instability of the ground connection is also a problem (particularly in mobile applications, where the modulation of impedance can cause the BNC to act as a surprisingly good vibration sensor). BNCs are also manufactured to fairly loose tolerances, so if the application demands accuracy and precision over a wide frequency range, BNCs aren't going to be a good choice.

So, it's not as if signals abruptly stop emerging from the BNC once you go above, say, 4GHz. It's more complicated than that. And whether a BNC is useful or not in a given circumstance depends very much on what performance you need in that particular case. The frequency "limit" will vary accordingly.

-- Cheers
Tom


-- 
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
420 Via Palou Mall
Stanford University
Stanford, CA 94305-4070
On 6/29/2024 10:58 AM, Jinxie via groups.io wrote:
Hi all,

According to this site: 

50 ohm BNC connectors are only good up to 4GHz and 75 ohm ones to 2GHz maximum. And yet - to take just one example - my best frequency counter, which accepts and can measure signals up to 22Ghz, uses 50 Ohm BNC sockets and seemingly works just fine with them. And yet it's not just the Historytools website which claims BNC is only good up to a few GHz; plenty of other sources say the same thing. What's going on here?

Thanks,
J. 
?

					


				
				
				
			

			
				

				

					
						
	
		
			
				
			
		
		

			
				
			
			
			

				
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							Re: BNC Frequency Limit
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
...And dont?forget Wangnet which uses a BNC alongside TNC in its contra-rotating ring topology.

Pete


				
					
					

					


On Sat, Jun 29, 2024 at 10:15?PM Chuck Harris via  <cfharris=[email protected]> wrote:
Probably only about 6 gadzillion were used on routers before

the inverse SMA became popular... But, no, they didn't catch

on in the test equipment world.



-Chuck Harris





On Sat, 29 Jun 2024 13:32:04 -0700 "Jinxie via "

<paul666=[email protected]> wrote:

> TNC are several orders of magnitude better than BNC IIRC. Far more

> phase stable (that's another aspect we haven't mentioned yet). Shame

> they never really caught on; bit like Betamax and VHS. :(

> 

> 

> 

> 

> 















					


				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: BNC Frequency Limit
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
Hi Jim,

I could be wrong but I'm not sure this is totally accurate....

"Regarding TNC connectors, they are common for military applications where you just can't rely on the bayonet mechanical connection of a BNC.? You don't want your connectors vibrating loose on your aircraft, after all. "

The last thing I'd want is for vibes to loosen a threaded connector, which can happen.? I had my head inside a B757 E-E bay a few years ago doing some experimentation and I had to contend with getting a "Type C" adapter so that I could connect into the antenna interface of a VHF comm radio.? Type-C is a bayoneted Type-N connector.

73.....Frank / WA3NHK


				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: BNC Frequency Limit
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				


A very interesting discussion. Who really knows how that S-D counter with MW input came to have a BNC!? Maybe a "factory special" made for some very particular user! (you can buy anything you want if you have the $$) Very, very odd. I agree with Chuck H. as I, as well, have had tons of SD counters starting with their knock-off of the HP5245 called the 1037, and going up into the 6245 and above series (I may still have some around somewhere). Never saw a BNC used in a test equipment design for over a few GHz (although, as pointed out, will probably work, even if lossy!)


Now, on to TNC: A threaded BNC type, used initially to 12 GHz then improved to 18 GHz, popular in avionics like the APR-25 radar warning receiver used extensively in 'Nam. It is more rugged than an SMA (and I would argue,easier to connect/disconnect inside a tight fighter jet A/C equipment bay without damage), smaller/lighter than a N, manufacture is relatively cheap, and so on. A BIG user was NASA, and particularly JPL on the DSN because of the low RF leakage spec provided by the threaded portion. Even though the innards are the same as a BNC, the bayonet shell of a BNC leaked enough to bother the folks dealing with the deep space stuff! I saw racks of 100 MHz frequency distribution stuff at Goldstone -Current stuff! All plumbed in TNC. A great connector for certain uses and definitely can be had cheaply! People have given me good stuff for Gratis that was TNC based.



				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: BNC Frequency Limit
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
Also, the E4440A PSA spectrum analyser operates to 26.5 GHz and it uses a special version of the N connector.

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: BNC Frequency Limit
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				

        
You'll find type N on an 8566 spectrum analyzer to 22 GHz.? I'd expect the spec an to be more demanding than the frequency counter.? My 5343A counter goes to 26.5 GHz and has a male APC 3.5 mm connector on it, while my 8566A spec an goes to 22 GHz and has a type N on it.

Regarding TNC connectors, they are common for military applications where you just can't rely on the bayonet mechanical connection of a BNC.? You don't want your connectors vibrating loose on your aircraft, after all.? Bonus that they support higher frequencies than BNC.? I've seen TNCs on handheld military radios, where a type N would be too bulky.

SMA was developed to be an inexpensive and compact way to connect to 18 GHz, since pushed in some cases to 26.5 GHz.? Amphenol and HP came up with the APC 3.5 mm connector for use in testing devices with SMAs on them and for use up to 26.5 GHz.? Wiltron, now part of Anritsu, one-upped HP with the 40 GHz 2.92 mm "K" connector.? 3.5 mm and 2.92 mm connectors are mechanically compatible with SMA.

HP was not about to buy connectors from a competitor and made their own 50 GHz 2.4 mm connector but made it incompatible with the SMA types.? Wiltron, IIRC, one-upped HP again with the 60+ GHz 1.85 mm "V" connector, which I believe is mechanically compatible with the 2.4 mm.? Then Southwest Microwave came out with the (very expensive) 1.0 mm connector for up to 110 GHz.? Since then, several German companies, I think Rosenberger and Spinner among them, came out with the 86 GHz 1.35 mm.? One would guess the idea was to handle E band, 71-86 GHz (with a hole in middle from 76 to 81 GHz) at a lower price point than the ~$1000 1.0 mm connector.? I've also heard rumors of 0.9 mm and 0.8 mm connectors to get up aroun 200 GHz(!)? I can only guess how much those would cost....

HTH

Jim Ford
Laguna Hills, California, USA 


        
        

            

                
                

                        On Saturday, June 29, 2024 at 04:43:50 PM CDT, Greg Muir via groups.io <big_sky_explorer@...> wrote:
                    

                    


                    


                
                
                
Systron-Donner 6054B ¨C the 20 MHz -24 GHZ connector on stock models certainly looks like an SMA to me.? The 20 Hz -20 MHZ input is a BNC.? The S-D catalog calls out (verbatim) ¡°SMA-3MM. Other input connectors available on special order.¡±

A BNC modification would nicely fit into the hole made for a SMA if a slight modification to the hole were made with no trace of any hacking.

Greg






            

        

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: BNC Frequency Limit
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
I suppose lots of things could have happened. It 'might' have had the BNC fitted from new as a factory option, but then again, it could be that the original SMA got damaged and the only bulkhead connector available for a quick repair was a BNC type.

Either way, I'd expect it to work quite well as a frequency counter up to 18GHz with a fairly decent BNC connector at the input. Above this, the input impedance could become quite different to 50R. As it is just a counter, this probably doesn't matter much so it will probably still function OK to 20GHz. I'd expect to see some issues above 20GHz but it might still function OK as a counter if driven with a level > -20dBm? 

By 24GHz there might be some dips in the response especially if it is fed from a source that doesn't have a well defined 50R source impedance above 18GHz. There could be some big (source to load mismatch) dips in the frequency response because of this. In other words, it might work OK to beyond 20GHz when tested with decent 50R test gear, but with a real world signal source with a relatively poor VSWR, there could be significant dips in the frequency response, especially when using a reasonably long piece of coax cable to make the connection to the counter.

However, not many people will use a frequency counter at these frequencies for real world applications in 2024. If you only plan to use it to 10GHz or even 18GHz I wouldn't worry too much about the BNC connector unless you actually end up with a frequency response problem one day.

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: BNC Frequency Limit
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
Systron-Donner 6054B ¨C the 20 MHz -24 GHZ connector on stock models certainly looks like an SMA to me.  The 20 Hz -20 MHZ input is a BNC.  The S-D catalog calls out (verbatim) ¡°SMA-3MM. Other input connectors available on special order.¡±

A BNC modification would nicely fit into the hole made for a SMA if a slight modification to the hole were made with no trace of any hacking.

Greg

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: BNC Frequency Limit
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
The datasheet for that 6054B counter does state that the input is normally an SMA connector. However, it also states that other connector types are available on special order. 

A standard BNC connector would be an odd choice to fit here though...

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: BNC Frequency Limit
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
Probably only about 6 gadzillion were used on routers before
the inverse SMA became popular... But, no, they didn't catch
on in the test equipment world.

-Chuck Harris


On Sat, 29 Jun 2024 13:32:04 -0700 "Jinxie via groups.io"
<paul666@...> wrote:
TNC are several orders of magnitude better than BNC IIRC. Far more
phase stable (that's another aspect we haven't mentioned yet). Shame
they never really caught on; bit like Betamax and VHS. :(





				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: BNC Frequency Limit
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
From what I have seen, the 6054B can have either a SMA style,
or an N style depending on the top frequency.  Never BNC.

If yours has a BNC on the microwave input, then someone must
have changed it... Probably because they broke the SMA style
connector.

I say SMA style, because it is more probably an APC 3.5.

-Chuck Harris


On Sat, 29 Jun 2024 12:54:19 -0700 "Jinxie via groups.io"
<paul666@...> wrote:
6054B and I can't post any pictures right now I'm afraid. It doesn't
appear that the BNC has been changed from SMA; looks original and why
would anyone do such a thing anyway? Does seem an odd choice!





				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
	

	
	
	
	


	

		
		
		
		
		
	

	

		
		
		
		
		
	

	
	

		
		
		
		
	



	

		

			
	
		

			
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