HP 8569B - low range extension possible ? - Page 1
Forum section: electronics / testgear

author: pfm
author_rank: Regular Contributor
timestamp: June 06, 2016, 03:29:21 pm
content: Inherited a HP 8569B. Range is 10Mhz to 22Ghz (yes thats ghz with a 'G'!). While I was looking to add a SA to my bench, and while I do some RF and VHF/UHF work now and then, most of my SA work would be in the lower range. Much lower - like 100Khz to maybe 10Mhz tops. This SA starts from that point. So my question is - Is there a way to 'extend' its low end range from 10Mhz to 100Khz ? Is so how ? I am open to DIY ideas.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 06, 2016, 04:40:31 pm
content: I still have one of those heavy old systems. Really, the only problem I have had with it was the 110/220 AC line selector card needed some help. Yes, you could make an up converter to convert the lower area you are interested in to a range the SA is able to read. Shown below is one I home made.Also below is a little IF decoder for it.I never did a whole lot with Labview using this instrument. The program will pull the information out so I could at least save the data for later but that was about it.If you are interested in making your own converter, the ARRL handbook may be a good place to start.Quote from: pfm on June 06, 2016, 03:29:21 pm

author: pfm
author_rank: Regular Contributor
timestamp: June 06, 2016, 05:42:11 pm
content: Thanks for your reply!In the first picture where there is an adapter plugged in to the SA and on the label it says "HP..spectrum analyzer upconverter" - is that something you built or is that an accessory available from HP ?I am a ham () and I did look into the diy mixer approach but I was worried there might be too much loss and distortion added by a diy mixer especially on a very low amplitude signals. Would you mind sharing some details about the one you made ?Did you look at ready made mixers like from Mini-Circuits and see if any of those would work ?Thanks.

author: TheSteve
author_rank: Unknown
timestamp: June 06, 2016, 08:26:15 pm
content: Depending on your requirements a Mini Circuits mixer may do the job for you if the HP has a reference out that is suitable.

author: pfm
author_rank: Regular Contributor
timestamp: June 08, 2016, 06:23:18 pm
content: Nicely done, really.I also like your advice about getting a lower range SA since I did see some nice ones on ebay that have the full range I am looking for. I could sell the 8569b and use the proceeds to fund that purchase.I don't think I need over 6Ghz which should cover the consumer 5ghz band. On the low end of the spectrum would be nice to have at least 100Khz or lower.Any models you or anyone would like to recommend ?Thanks!

author: pfm
author_rank: Regular Contributor
timestamp: July 14, 2016, 06:34:04 pm
content: Hi Joeqsmith,are you aware about this ? -http://www.nooelec.com/store/ham-it-up.htmlNo idea what the specs are but look interesting for this purpose.

author: cncjerry
author_rank: Unknown
timestamp: July 14, 2016, 08:53:08 pm
content: There was a really nice up-converter in QEX a while back. I can't remember the target SA. Send me a PM if you fail to find the issue. The guy who built it might have boards available.