Re: Transmission lines, Input match and Connectors #bestpractice #experiment


jdow
 

Type-N is not much better than BNC. If the shell is pulled off a type N or BNC male you can "accidentally" plug BNC into N or N into BNC. If you want precision you want something like APC-7 or SMA.

{o.o}

On 20191020 16:35:57, doug wrote:
On 10/19/2019 10:20 PM, jdow wrote:
Um, tell that to HP.

BNC barrel attenuators are good probably to 20 dB. I have lower
attenuation units - 3 dB and 6 dB sort of things. (At HF I like to use
them because they provide a nice leakage path to deal with static build
up issues.)

{o.o}

On 20191019 13:02:42, doug wrote:

/snip/
 I do have
some BNC coaxial attenuators I can use. I have to dig them out. It's an
archeological expedition time.

{^_^}
Hi, Joanne--
Surely you of all people know that BNC attenuators are not very good
attenuators at any VHF or higher frequency. Fine for HF, unless you need
a lot of attenuation.

--doug, WA2SAY
Well, you do agree that BNC attenuators are only really useful at HF. Good. I am concerned about a blanket recommendation of BNC attenuators
among those who are not experienced in the RF field. I would endorse TNC
types, at least to 1 GHz, altho they are not in common use, and certainly Type N, all the way to X-Band, at least. If anyone reading this is considering buying attenuators for RF and microwave frequencies,
please go to Google and check the manufacturer's specifications first!
Do check e-bay--sometimes you get lucky! (When you get the device, test
it with an ohmmeter! It could have been blown out by exposure to high power. If so, send it back!)
(Thank goodness, there are [to my knowledge] no UHF attenuators.  I have been campaigning [without success] against all use of UHF connectors for any RF use for years! All my radios and antennas are
connected thru adapters to type N or BNC. At least BNC's are 50 Ohms,
even if they do leak RF. And they don't take a 200 Watt soldering
iron to assemble to coax!)
--doug, WA2say

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