Attenuator Decade 0 - 140 dB / DC - 18 GHz - Page 1
Forum section: electronics / projects

author: max-bit
author_rank: Frequent Contributor
timestamp: September 04, 2015, 09:10:35 pm
content: This small projectAttenuator Decade 0 - 140 dBDC - 18 GHzSo when the input signal-values of + 20dBm at the output value will be suppressed with a value of -120dBm or 0,223uV / 50omThe components used (Price for one piece):Gates HP 33321B x2 0-70 dB price of abou 50 EuroHAMMOND case 1455R1602BK price of 30 EuroSMA socket 1051018-1 TE price 20 EuroSemirigid RG405 cable x3 (USED)SMA connectors 1050548-1 price 5 EuroKnobs x2 price 3 EuroThe total cost of 200 EuroFull info on webhttp://mikrofale.iq24.pl/default.asp?grupa=160341&temat=426576&nr_str=1

author: German_EE
author_rank: Super Contributor
timestamp: September 04, 2015, 09:14:34 pm
content: The above link just leads to another forum. Are construction details available for this project because the specifications are impressive.

author: max-bit
author_rank: Frequent Contributor
timestamp: September 04, 2015, 09:34:36 pm
content: I give full details as I have finally made attenuator

author: tggzzz
author_rank: Super Contributor
timestamp: September 04, 2015, 10:51:10 pm
content: Quote from: max-bit on September 04, 2015, 09:34:36 pmPlease go one step further and present themeasuredperformance. Preferably including the input and output return loss and phase change as a function of frequency and attenuation

author: rfeecs
author_rank: Frequent Contributor
timestamp: September 04, 2015, 11:11:31 pm
content: So you are sticking two HP step attenuators in a box?

author: retrolefty
author_rank: Super Contributor
timestamp: September 04, 2015, 11:15:19 pm
content: Quote from: tggzzz on September 04, 2015, 10:51:10 pmNot tryival to measure actual performance with that freq and amplitude range. Short of a 0-18 GHz SA with tracking generator, how would one go about 'testing' this with more hobbyist available test equipment.

author: tggzzz
author_rank: Super Contributor
timestamp: September 04, 2015, 11:45:27 pm
content: Quote from: retrolefty on September 04, 2015, 11:15:19 pmJust so.It is much easier to simplyclaima specification and build something (or other).

author: max-bit
author_rank: Frequent Contributor
timestamp: September 05, 2015, 04:45:06 am
content: 1. For the attenuator will be used 2 original silencers HP (agilnet) 33321B2. Measurements of the full extent I can perform up to 4.4 GHz3. Details of give ....... execute attenuatorHere are a few basic measurements suppression1 GHz input power +10dBm2 GHz input power -130dBm2 GHz - 140 dBm input power 0 dBm

author: ywara
author_rank: Contributor
timestamp: September 05, 2015, 04:21:54 pm
content: I'm fairly surprised you managed to get two working HP step attenuators. They are not very robust and it is quite normal for them to fail due to poor grounding long before their rated life. The edge-line design is quite good, but they never seem to have gotten their material issues resolved.

author: max-bit
author_rank: Frequent Contributor
timestamp: September 07, 2015, 02:33:02 pm
content: I have a questionAre these HP attenuator are bi-directional or not bi-directional ?In the literature, a word about it and you can tell that they are non-directional ... No information available.In the drawings, the HP show that the left is the input on the right side output.

author: ywara
author_rank: Contributor
timestamp: September 07, 2015, 07:08:39 pm
content: No, they are not directional. It is possible that the impedance match is better controlled at the input, but they should function regardless of orientation.

author: max-bit
author_rank: Frequent Contributor
timestamp: September 08, 2015, 04:09:46 am
content: OK thanksso I thought

author: max-bit
author_rank: Frequent Contributor
timestamp: September 11, 2015, 06:21:49 pm
content: Final ....

author: Dave
author_rank: Super Contributor
timestamp: September 12, 2015, 03:08:24 pm
content: Does the copper tape actually make a difference? Isn't semi-rigid coax enough for good signal isolation?

author: max-bit
author_rank: Frequent Contributor
timestamp: September 13, 2015, 04:55:25 pm
content: I gave additional shielding, it would not hurt

author: Richard Head
author_rank: Frequent Contributor
timestamp: September 14, 2015, 07:27:00 am
content: The bend radii of the semi-rigid coax is too tight in my opinion. I think you should have used a loop for each one.Also, I would have been inclined to move the two SMA's much further apart to reduce coupling between input and output. It probably wouldn't be a problem with semi-rigid coax leads but could be if flexible coax is used. Nice job.

author: VK5RC
author_rank: Unknown
timestamp: September 14, 2015, 11:11:02 am
content: I have found the 'programmable' HP microwave attenuators go for a lot cheaper (often < half price) and built a simple circuit (several switches, a 9v battery and a push button) to change attenuation.

author: max-bit
author_rank: Frequent Contributor
timestamp: September 19, 2015, 07:23:18 am
content: This can be done programmable relays.But that power is needed, and it's always a downsideIf there is anyone interested I can get sell attenuator HP's 33321B price of $ 95 apiece (without knobs)http://mikrofale.iq24.pl/default.asp?grupa=160341&temat=426576&nr_str=2Final version

author: Simon
author_rank: Unknown
timestamp: September 19, 2015, 07:52:39 am
content: Quote from: max-bit on September 19, 2015, 07:23:18 amDo you ever stop trying to sell stuff ? I am continually getting reports of just lists of ebay items in the buy sell section that are just computer bits and every other post around here your pricing stuff up. Why don't you just take an advert out ? my patience wears thin.