There is an ETF (Exchange Traded Fund) that trades under the symbol JTP (Nuveen Quality Preferred Income Fund) that closed today at $13.40 and pays 8.7% and they pay the first of each month. Like any fund, you get some safety in diversification. Lou
I have a fair amount of preferreds, trust preferreds (really a debt security) and preferred REITs. Sold all my regular REITs and waiting to get back in later this year with LUM and IMH, but these are hardly "conservative." REIT preferreds I hold now include AHR-C, ANH-A, IMH-B, and IMH-C. Advise you buy any of these at not much more than their $25 redemption value. Also looking to buy after the May 11th ex-div date the following, if they drop more than the quarterly divvie payment: SRC, EP-A, ILD.
Go to www (dot) quantumonline (dot) com for free and excellent lists of preferred and preferred-like securities. Read the descriptions very carefully so you know what you are buying, some pay qualified dividends, other hybrid preferreds are backed by debt securities and are taxed as regular interest. I currently own RMT-A, ABN-E, PFACP, PJJ, ABS-, NVP-B, PFH, SBGIP. If you are looking up these in Yahoo, those with a dash have a different Yahoo Finance symbol, eg, EP-A is EP-PA in Yahoo.
You also might want to look at the so-called IDS issues. I own BGF, OTT and CVP, they all yield 10%+, a combination of dividend and interest payments, but they are riskier than most preferreds because these are operating companies that must maintain enough cash flow to keep paying the dividends.
Two others are phone companies that pay 8% to 10%, CZN (primarily rural USA) and CTC (a Chilean company), I am looking at those on a drop of about 5% from current stock price.